]> git.sesse.net Git - movit/blobdiff - effect_chain_test.cpp
Remove sandbox_effect from coverage.
[movit] / effect_chain_test.cpp
index 778259f7da5ca7961510a9739d9915e491e21698..ab71b4b5026ebfd1b5649849f5754700ed85ee4f 100644 (file)
@@ -2,13 +2,22 @@
 //
 // Note that this also contains the tests for some of the simpler effects.
 
+#include <GL/glew.h>
+#include <assert.h>
+
+#include "effect.h"
 #include "effect_chain.h"
 #include "flat_input.h"
 #include "gtest/gtest.h"
+#include "init.h"
+#include "input.h"
 #include "mirror_effect.h"
+#include "multiply_effect.h"
 #include "resize_effect.h"
-#include "opengl.h"
 #include "test_util.h"
+#include "util.h"
+
+using namespace std;
 
 TEST(EffectChainTest, EmptyChain) {
        float data[] = {
@@ -26,8 +35,8 @@ TEST(EffectChainTest, EmptyChain) {
 class IdentityEffect : public Effect {
 public:
        IdentityEffect() {}
-       virtual std::string effect_type_id() const { return "IdentityEffect"; }
-       std::string output_fragment_shader() { return read_file("identity.frag"); }
+       virtual string effect_type_id() const { return "IdentityEffect"; }
+       string output_fragment_shader() { return read_file("identity.frag"); }
 };
 
 TEST(EffectChainTest, Identity) {
@@ -47,9 +56,10 @@ TEST(EffectChainTest, Identity) {
 class BouncingIdentityEffect : public Effect {
 public:
        BouncingIdentityEffect() {}
-       virtual std::string effect_type_id() const { return "IdentityEffect"; }
-       std::string output_fragment_shader() { return read_file("identity.frag"); }
+       virtual string effect_type_id() const { return "IdentityEffect"; }
+       string output_fragment_shader() { return read_file("identity.frag"); }
        bool needs_texture_bounce() const { return true; }
+       AlphaHandling alpha_handling() const { return DONT_CARE_ALPHA_TYPE; }
 };
 
 TEST(EffectChainTest, TextureBouncePreservesIdentity) {
@@ -86,29 +96,32 @@ TEST(MirrorTest, BasicTest) {
 class InvertEffect : public Effect {
 public:
        InvertEffect() {}
-       virtual std::string effect_type_id() const { return "InvertEffect"; }
-       std::string output_fragment_shader() { return read_file("invert_effect.frag"); }
+       virtual string effect_type_id() const { return "InvertEffect"; }
+       string output_fragment_shader() { return read_file("invert_effect.frag"); }
+
+       // A real invert would actually care about its alpha,
+       // but in this unit test, it only complicates things.
+       virtual AlphaHandling alpha_handling() const { return DONT_CARE_ALPHA_TYPE; }
 };
 
 // Like IdentityEffect, but rewrites itself out of the loop,
-// splicing in a InvertEffect instead. Also stores the new node,
-// so we later can check that there are gamma conversion effects
-// on both sides.
-class RewritingToInvertEffect : public Effect {
+// splicing in a different effect instead. Also stores the new node,
+// so we later can check whatever properties we'd like about the graph.
+template<class T>
+class RewritingEffect : public Effect {
 public:
-       RewritingToInvertEffect() {}
-       virtual std::string effect_type_id() const { return "RewritingToInvertEffect"; }
-       std::string output_fragment_shader() { EXPECT_TRUE(false); return read_file("identity.frag"); }
+       RewritingEffect() : effect(new T()), replaced_node(NULL) {}
+       virtual string effect_type_id() const { return "RewritingEffect[" + effect->effect_type_id() + "]"; }
+       string output_fragment_shader() { EXPECT_TRUE(false); return read_file("identity.frag"); }
        virtual void rewrite_graph(EffectChain *graph, Node *self) {
-               Node *invert_node = graph->add_node(new InvertEffect());
-               graph->replace_receiver(self, invert_node);
-               graph->replace_sender(self, invert_node);
-
+               replaced_node = graph->add_node(effect);
+               graph->replace_receiver(self, replaced_node);
+               graph->replace_sender(self, replaced_node);
                self->disabled = true;
-               this->invert_node = invert_node;
        }
 
-       Node *invert_node;      
+       T *effect;
+       Node *replaced_node;
 };
 
 TEST(EffectChainTest, RewritingWorksAndGammaConversionsAreInserted) {
@@ -122,11 +135,11 @@ TEST(EffectChainTest, RewritingWorksAndGammaConversionsAreInserted) {
        };
        float out_data[6];
        EffectChainTester tester(data, 3, 2, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
-       RewritingToInvertEffect *effect = new RewritingToInvertEffect();
+       RewritingEffect<InvertEffect> *effect = new RewritingEffect<InvertEffect>();
        tester.get_chain()->add_effect(effect);
        tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_sRGB);
 
-       Node *node = effect->invert_node;
+       Node *node = effect->replaced_node;
        ASSERT_EQ(1, node->incoming_links.size());
        ASSERT_EQ(1, node->outgoing_links.size());
        EXPECT_EQ("GammaExpansionEffect", node->incoming_links[0]->effect->effect_type_id());
@@ -135,6 +148,31 @@ TEST(EffectChainTest, RewritingWorksAndGammaConversionsAreInserted) {
        expect_equal(expected_data, out_data, 3, 2);
 }
 
+TEST(EffectChainTest, RewritingWorksAndTexturesAreAskedForsRGB) {
+       unsigned char data[] = {
+               0, 64,
+               128, 255,
+       };
+       float expected_data[4] = {
+               1.0f, 0.9771f,
+               0.8983f, 0.0f,
+       };
+       float out_data[4];
+       EffectChainTester tester(NULL, 2, 2);
+       tester.add_input(data, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
+       RewritingEffect<InvertEffect> *effect = new RewritingEffect<InvertEffect>();
+       tester.get_chain()->add_effect(effect);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_sRGB);
+
+       Node *node = effect->replaced_node;
+       ASSERT_EQ(1, node->incoming_links.size());
+       ASSERT_EQ(1, node->outgoing_links.size());
+       EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
+       EXPECT_EQ("GammaCompressionEffect", node->outgoing_links[0]->effect->effect_type_id());
+
+       expect_equal(expected_data, out_data, 2, 2);
+}
+
 TEST(EffectChainTest, RewritingWorksAndColorspaceConversionsAreInserted) {
        float data[] = {
                0.0f, 0.25f, 0.3f,
@@ -146,11 +184,11 @@ TEST(EffectChainTest, RewritingWorksAndColorspaceConversionsAreInserted) {
        };
        float out_data[6];
        EffectChainTester tester(data, 3, 2, FORMAT_GRAYSCALE, COLORSPACE_REC_601_525, GAMMA_LINEAR);
-       RewritingToInvertEffect *effect = new RewritingToInvertEffect();
+       RewritingEffect<InvertEffect> *effect = new RewritingEffect<InvertEffect>();
        tester.get_chain()->add_effect(effect);
        tester.run(out_data, GL_RED, COLORSPACE_REC_601_525, GAMMA_LINEAR);
 
-       Node *node = effect->invert_node;
+       Node *node = effect->replaced_node;
        ASSERT_EQ(1, node->incoming_links.size());
        ASSERT_EQ(1, node->outgoing_links.size());
        EXPECT_EQ("ColorspaceConversionEffect", node->incoming_links[0]->effect->effect_type_id());
@@ -159,25 +197,61 @@ TEST(EffectChainTest, RewritingWorksAndColorspaceConversionsAreInserted) {
        expect_equal(expected_data, out_data, 3, 2);
 }
 
-// Like RewritingToInvertEffect, but splicing in a MirrorEffect instead,
-// which does not need linear light or sRGB primaries.
-class RewritingToMirrorEffect : public Effect {
+// A fake input that can change its output colorspace and gamma between instantiation
+// and finalize.
+class UnknownColorspaceInput : public FlatInput {
 public:
-       RewritingToMirrorEffect() {}
-       virtual std::string effect_type_id() const { return "RewritingToMirrorEffect"; }
-       std::string output_fragment_shader() { EXPECT_TRUE(false); return read_file("identity.frag"); }
-       virtual void rewrite_graph(EffectChain *graph, Node *self) {
-               Node *mirror_node = graph->add_node(new MirrorEffect());
-               graph->replace_receiver(self, mirror_node);
-               graph->replace_sender(self, mirror_node);
+       UnknownColorspaceInput(ImageFormat format, MovitPixelFormat pixel_format, GLenum type, unsigned width, unsigned height)
+           : FlatInput(format, pixel_format, type, width, height),
+             overridden_color_space(format.color_space),
+             overridden_gamma_curve(format.gamma_curve) {}
+       virtual string effect_type_id() const { return "UnknownColorspaceInput"; }
 
-               self->disabled = true;
-               this->mirror_node = mirror_node;
+       void set_color_space(Colorspace colorspace) {
+               overridden_color_space = colorspace;
        }
+       void set_gamma_curve(GammaCurve gamma_curve) {
+               overridden_gamma_curve = gamma_curve;
+       }
+       Colorspace get_color_space() const { return overridden_color_space; }
+       GammaCurve get_gamma_curve() const { return overridden_gamma_curve; }
 
-       Node *mirror_node;
+private:
+       Colorspace overridden_color_space;
+       GammaCurve overridden_gamma_curve;
 };
 
+TEST(EffectChainTester, HandlesInputChangingColorspace) {
+       const int size = 4;
+
+       float data[size] = {
+               0.0,
+               0.5,
+               0.7,
+               1.0,
+       };
+       float out_data[size];
+
+       EffectChainTester tester(NULL, 4, 1, FORMAT_GRAYSCALE);
+
+       // First say that we have sRGB, linear input.
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       UnknownColorspaceInput *input = new UnknownColorspaceInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 4, 1);
+       input->set_pixel_data(data);
+       tester.get_chain()->add_input(input);
+
+       // Now we change to Rec. 601 input.
+       input->set_color_space(COLORSPACE_REC_601_625);
+       input->set_gamma_curve(GAMMA_REC_601);
+
+       // Now ask for Rec. 601 output. Thus, our chain should now be a no-op.
+       tester.run(out_data, GL_RED, COLORSPACE_REC_601_625, GAMMA_REC_601);
+       expect_equal(data, out_data, 4, 1);
+}
+
 TEST(EffectChainTest, NoGammaConversionsWhenLinearLightNotNeeded) {
        float data[] = {
                0.0f, 0.25f, 0.3f,
@@ -189,11 +263,11 @@ TEST(EffectChainTest, NoGammaConversionsWhenLinearLightNotNeeded) {
        };
        float out_data[6];
        EffectChainTester tester(data, 3, 2, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
-       RewritingToMirrorEffect *effect = new RewritingToMirrorEffect();
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
        tester.get_chain()->add_effect(effect);
        tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_sRGB);
 
-       Node *node = effect->mirror_node;
+       Node *node = effect->replaced_node;
        ASSERT_EQ(1, node->incoming_links.size());
        EXPECT_EQ(0, node->outgoing_links.size());
        EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
@@ -212,11 +286,11 @@ TEST(EffectChainTest, NoColorspaceConversionsWhensRGBPrimariesNotNeeded) {
        };
        float out_data[6];
        EffectChainTester tester(data, 3, 2, FORMAT_GRAYSCALE, COLORSPACE_REC_601_525, GAMMA_LINEAR);
-       RewritingToMirrorEffect *effect = new RewritingToMirrorEffect();
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
        tester.get_chain()->add_effect(effect);
        tester.run(out_data, GL_RED, COLORSPACE_REC_601_525, GAMMA_LINEAR);
 
-       Node *node = effect->mirror_node;
+       Node *node = effect->replaced_node;
        ASSERT_EQ(1, node->incoming_links.size());
        EXPECT_EQ(0, node->outgoing_links.size());
        EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
@@ -239,6 +313,23 @@ TEST(EffectChainTest, IdentityThroughsRGBConversions) {
        expect_equal(data, out_data, 256, 1);
 }
 
+// Same, but uses the forward sRGB table from the GPU.
+TEST(EffectChainTest, IdentityThroughGPUsRGBConversions) {
+       unsigned char data[256];
+       float expected_data[256];
+       for (unsigned i = 0; i < 256; ++i) {
+               data[i] = i;
+               expected_data[i] = i / 255.0;
+       };
+       float out_data[256];
+       EffectChainTester tester(NULL, 256, 1);
+       tester.add_input(data, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
+       tester.get_chain()->add_effect(new IdentityEffect());
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_sRGB);
+
+       expect_equal(expected_data, out_data, 256, 1);
+}
+
 // Same, for the Rec. 601/709 gamma curve.
 TEST(EffectChainTest, IdentityThroughRec709) {
        float data[256];
@@ -253,15 +344,185 @@ TEST(EffectChainTest, IdentityThroughRec709) {
        expect_equal(data, out_data, 256, 1);
 }
 
+// The identity effect needs premultiplied alpha, and thus will get conversions on both sides.
+TEST(EffectChainTest, IdentityThroughAlphaConversions) {
+       const int size = 3;
+       float data[4 * size] = {
+               0.8f, 0.0f, 0.0f, 0.5f,
+               0.0f, 0.2f, 0.2f, 0.3f,
+               0.1f, 0.0f, 1.0f, 1.0f,
+       };
+       float out_data[4 * size];
+       EffectChainTester tester(data, size, 1, FORMAT_RGBA_POSTMULTIPLIED_ALPHA, COLORSPACE_sRGB, GAMMA_LINEAR);
+       tester.get_chain()->add_effect(new IdentityEffect());
+       tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(data, out_data, 4, size);
+}
+
+TEST(EffectChainTest, NoAlphaConversionsWhenPremultipliedAlphaNotNeeded) {
+       const int size = 3;
+       float data[4 * size] = {
+               0.8f, 0.0f, 0.0f, 0.5f,
+               0.0f, 0.2f, 0.2f, 0.3f,
+               0.1f, 0.0f, 1.0f, 1.0f,
+       };
+       float expected_data[4 * size] = {
+               0.1f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.2f, 0.2f, 0.3f,
+               0.8f, 0.0f, 0.0f, 0.5f,
+       };
+       float out_data[4 * size];
+       EffectChainTester tester(data, size, 1, FORMAT_RGBA_POSTMULTIPLIED_ALPHA, COLORSPACE_sRGB, GAMMA_LINEAR);
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
+       tester.get_chain()->add_effect(effect);
+       tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       Node *node = effect->replaced_node;
+       ASSERT_EQ(1, node->incoming_links.size());
+       EXPECT_EQ(0, node->outgoing_links.size());
+       EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
+
+       expect_equal(expected_data, out_data, 4, size);
+}
+
+// An input that outputs only blue, which has blank alpha.
+class BlueInput : public Input {
+public:
+       BlueInput() { register_int("needs_mipmaps", &needs_mipmaps); }
+       virtual string effect_type_id() const { return "IdentityEffect"; }
+       string output_fragment_shader() { return read_file("blue.frag"); }
+       virtual AlphaHandling alpha_handling() const { return OUTPUT_BLANK_ALPHA; }
+       virtual void finalize() {}
+       virtual bool can_output_linear_gamma() const { return true; }
+       virtual unsigned get_width() const { return 1; }
+       virtual unsigned get_height() const { return 1; }
+       virtual Colorspace get_color_space() const { return COLORSPACE_sRGB; }
+       virtual GammaCurve get_gamma_curve() const { return GAMMA_LINEAR; }
+
+private:
+       int needs_mipmaps;
+};
+
+// Like RewritingEffect<InvertEffect>, but splicing in a BlueInput instead,
+// which outputs blank alpha.
+class RewritingToBlueInput : public Input {
+public:
+       RewritingToBlueInput() : blue_node(NULL) { register_int("needs_mipmaps", &needs_mipmaps); }
+       virtual string effect_type_id() const { return "RewritingToBlueInput"; }
+       string output_fragment_shader() { EXPECT_TRUE(false); return read_file("identity.frag"); }
+       virtual void rewrite_graph(EffectChain *graph, Node *self) {
+               Node *blue_node = graph->add_node(new BlueInput());
+               graph->replace_receiver(self, blue_node);
+               graph->replace_sender(self, blue_node);
+
+               self->disabled = true;
+               this->blue_node = blue_node;
+       }
+
+       // Dummy values that we need to implement because we inherit from Input.
+       // Same as BlueInput.
+       virtual AlphaHandling alpha_handling() const { return OUTPUT_BLANK_ALPHA; }
+       virtual void finalize() {}
+       virtual bool can_output_linear_gamma() const { return true; }
+       virtual unsigned get_width() const { return 1; }
+       virtual unsigned get_height() const { return 1; }
+       virtual Colorspace get_color_space() const { return COLORSPACE_sRGB; }
+       virtual GammaCurve get_gamma_curve() const { return GAMMA_LINEAR; }
+
+       Node *blue_node;
+
+private:
+       int needs_mipmaps;
+};
+
+TEST(EffectChainTest, NoAlphaConversionsWithBlankAlpha) {
+       const int size = 3;
+       float data[4 * size] = {
+               0.0f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.0f, 1.0f, 1.0f,
+       };
+       float out_data[4 * size];
+       EffectChainTester tester(NULL, size, 1);
+       RewritingToBlueInput *input = new RewritingToBlueInput();
+       tester.get_chain()->add_input(input);
+       tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_LINEAR, OUTPUT_ALPHA_FORMAT_PREMULTIPLIED);
+
+       Node *node = input->blue_node;
+       EXPECT_EQ(0, node->incoming_links.size());
+       EXPECT_EQ(0, node->outgoing_links.size());
+
+       expect_equal(data, out_data, 4, size);
+}
+
+// An effect that does nothing, and specifies that it preserves blank alpha.
+class BlankAlphaPreservingEffect : public Effect {
+public:
+       BlankAlphaPreservingEffect() {}
+       virtual string effect_type_id() const { return "BlankAlphaPreservingEffect"; }
+       string output_fragment_shader() { return read_file("identity.frag"); }
+       virtual AlphaHandling alpha_handling() const { return INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK; }
+};
+
+TEST(EffectChainTest, NoAlphaConversionsWithBlankAlphaPreservingEffect) {
+       const int size = 3;
+       float data[4 * size] = {
+               0.0f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.0f, 1.0f, 1.0f,
+       };
+       float out_data[4 * size];
+       EffectChainTester tester(NULL, size, 1);
+       tester.get_chain()->add_input(new BlueInput());
+       tester.get_chain()->add_effect(new BlankAlphaPreservingEffect());
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
+       tester.get_chain()->add_effect(effect);
+       tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_LINEAR, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
+
+       Node *node = effect->replaced_node;
+       EXPECT_EQ(1, node->incoming_links.size());
+       EXPECT_EQ(0, node->outgoing_links.size());
+
+       expect_equal(data, out_data, 4, size);
+}
+
+// This is the counter-test to NoAlphaConversionsWithBlankAlphaPreservingEffect;
+// just to be sure that with a normal INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA effect,
+// an alpha conversion _should_ be inserted at the very end. (There is some overlap
+// with other tests.)
+TEST(EffectChainTest, AlphaConversionsWithNonBlankAlphaPreservingEffect) {
+       const int size = 3;
+       float data[4 * size] = {
+               0.0f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.0f, 1.0f, 1.0f,
+               0.0f, 0.0f, 1.0f, 1.0f,
+       };
+       float out_data[4 * size];
+       EffectChainTester tester(NULL, size, 1);
+       tester.get_chain()->add_input(new BlueInput());
+       tester.get_chain()->add_effect(new IdentityEffect());  // Not BlankAlphaPreservingEffect.
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
+       tester.get_chain()->add_effect(effect);
+       tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_LINEAR, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
+
+       Node *node = effect->replaced_node;
+       EXPECT_EQ(1, node->incoming_links.size());
+       EXPECT_EQ(1, node->outgoing_links.size());
+       EXPECT_EQ("AlphaDivisionEffect", node->outgoing_links[0]->effect->effect_type_id());
+
+       expect_equal(data, out_data, 4, size);
+}
+
 // Effectively scales down its input linearly by 4x (and repeating it),
 // which is not attainable without mipmaps.
 class MipmapNeedingEffect : public Effect {
 public:
        MipmapNeedingEffect() {}
        virtual bool needs_mipmaps() const { return true; }
-       virtual std::string effect_type_id() const { return "MipmapNeedingEffect"; }
-       std::string output_fragment_shader() { return read_file("mipmap_needing_effect.frag"); }
-       void set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
+       virtual string effect_type_id() const { return "MipmapNeedingEffect"; }
+       string output_fragment_shader() { return read_file("mipmap_needing_effect.frag"); }
+       void set_gl_state(GLuint glsl_program_num, const string& prefix, unsigned *sampler_num)
        {
                glActiveTexture(GL_TEXTURE0);
                check_error();
@@ -380,3 +641,385 @@ TEST(EffectChainTest, ResizeDownByFourThenUpByFour) {
 
        expect_equal(expected_data, out_data, 4, 16);
 }
+
+// An effect that adds its two inputs together. Used below.
+class AddEffect : public Effect {
+public:
+       AddEffect() {}
+       virtual string effect_type_id() const { return "AddEffect"; }
+       string output_fragment_shader() { return read_file("add.frag"); }
+       virtual unsigned num_inputs() const { return 2; }
+       virtual AlphaHandling alpha_handling() const { return DONT_CARE_ALPHA_TYPE; }
+};
+
+// Constructs the graph
+//
+//             FlatInput               |
+//            /         \              |
+//  MultiplyEffect  MultiplyEffect     |
+//            \         /              |
+//             AddEffect               |
+//
+// and verifies that it gives the correct output.
+TEST(EffectChainTest, DiamondGraph) {
+       float data[] = {
+               1.0f, 1.0f,
+               1.0f, 0.0f,
+       };
+       float expected_data[] = {
+               2.5f, 2.5f,
+               2.5f, 0.0f,
+       };
+       float out_data[2 * 2];
+
+       const float half[] = { 0.5f, 0.5f, 0.5f, 0.5f };
+       const float two[] = { 2.0f, 2.0f, 2.0f, 0.5f };
+
+       MultiplyEffect *mul_half = new MultiplyEffect();
+       ASSERT_TRUE(mul_half->set_vec4("factor", half));
+       
+       MultiplyEffect *mul_two = new MultiplyEffect();
+       ASSERT_TRUE(mul_two->set_vec4("factor", two));
+
+       EffectChainTester tester(NULL, 2, 2);
+
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       FlatInput *input = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 2, 2);
+       input->set_pixel_data(data);
+
+       tester.get_chain()->add_input(input);
+       tester.get_chain()->add_effect(mul_half, input);
+       tester.get_chain()->add_effect(mul_two, input);
+       tester.get_chain()->add_effect(new AddEffect(), mul_half, mul_two);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, 2, 2);
+}
+
+// Constructs the graph
+//
+//             FlatInput                     |
+//            /         \                    |
+//  MultiplyEffect  MultiplyEffect           |
+//         \             |                   |
+//          \    BouncingIdentityEffect      |  
+//            \         /                    |
+//             AddEffect                     |
+//
+// and verifies that it gives the correct output.
+TEST(EffectChainTest, DiamondGraphWithOneInputUsedInTwoPhases) {
+       float data[] = {
+               1.0f, 1.0f,
+               1.0f, 0.0f,
+       };
+       float expected_data[] = {
+               2.5f, 2.5f,
+               2.5f, 0.0f,
+       };
+       float out_data[2 * 2];
+
+       const float half[] = { 0.5f, 0.5f, 0.5f, 0.5f };
+       const float two[] = { 2.0f, 2.0f, 2.0f, 0.5f };
+
+       MultiplyEffect *mul_half = new MultiplyEffect();
+       ASSERT_TRUE(mul_half->set_vec4("factor", half));
+       
+       MultiplyEffect *mul_two = new MultiplyEffect();
+       ASSERT_TRUE(mul_two->set_vec4("factor", two));
+       
+       BouncingIdentityEffect *bounce = new BouncingIdentityEffect();
+
+       EffectChainTester tester(NULL, 2, 2);
+
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       FlatInput *input = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 2, 2);
+       input->set_pixel_data(data);
+
+       tester.get_chain()->add_input(input);
+       tester.get_chain()->add_effect(mul_half, input);
+       tester.get_chain()->add_effect(mul_two, input);
+       tester.get_chain()->add_effect(bounce, mul_two);
+       tester.get_chain()->add_effect(new AddEffect(), mul_half, bounce);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, 2, 2);
+}
+
+TEST(EffectChainTest, EffectUsedTwiceOnlyGetsOneGammaConversion) {
+       float data[] = {
+               0.735f, 0.0f,
+               0.735f, 0.0f,
+       };
+       float expected_data[] = {
+               0.0f, 0.5f,  // 0.5 and not 1.0, since AddEffect doesn't clamp alpha properly.
+               0.0f, 0.5f,
+       };
+       float out_data[2 * 2];
+       
+       EffectChainTester tester(NULL, 2, 2);
+       tester.add_input(data, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
+
+       // MirrorEffect does not get linear light, so the conversions will be
+       // inserted after it, not before.
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
+       tester.get_chain()->add_effect(effect);
+
+       Effect *identity1 = tester.get_chain()->add_effect(new IdentityEffect(), effect);
+       Effect *identity2 = tester.get_chain()->add_effect(new IdentityEffect(), effect);
+       tester.get_chain()->add_effect(new AddEffect(), identity1, identity2);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, 2, 2);
+
+       Node *node = effect->replaced_node;
+       ASSERT_EQ(1, node->incoming_links.size());
+       ASSERT_EQ(1, node->outgoing_links.size());
+       EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
+       EXPECT_EQ("GammaExpansionEffect", node->outgoing_links[0]->effect->effect_type_id());
+}
+
+TEST(EffectChainTest, EffectUsedTwiceOnlyGetsOneColorspaceConversion) {
+       float data[] = {
+               0.5f, 0.0f,
+               0.5f, 0.0f,
+       };
+       float expected_data[] = {
+               0.0f, 0.5f,  // 0.5 and not 1.0, since AddEffect doesn't clamp alpha properly.
+               0.0f, 0.5f,
+       };
+       float out_data[2 * 2];
+       
+       EffectChainTester tester(NULL, 2, 2);
+       tester.add_input(data, FORMAT_GRAYSCALE, COLORSPACE_REC_601_625, GAMMA_LINEAR);
+
+       // MirrorEffect does not get linear light, so the conversions will be
+       // inserted after it, not before.
+       RewritingEffect<MirrorEffect> *effect = new RewritingEffect<MirrorEffect>();
+       tester.get_chain()->add_effect(effect);
+
+       Effect *identity1 = tester.get_chain()->add_effect(new IdentityEffect(), effect);
+       Effect *identity2 = tester.get_chain()->add_effect(new IdentityEffect(), effect);
+       tester.get_chain()->add_effect(new AddEffect(), identity1, identity2);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, 2, 2);
+
+       Node *node = effect->replaced_node;
+       ASSERT_EQ(1, node->incoming_links.size());
+       ASSERT_EQ(1, node->outgoing_links.size());
+       EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
+       EXPECT_EQ("ColorspaceConversionEffect", node->outgoing_links[0]->effect->effect_type_id());
+}
+
+// An effect that does nothing, but requests texture bounce and stores
+// its input size.
+class SizeStoringEffect : public BouncingIdentityEffect {
+public:
+       SizeStoringEffect() : input_width(-1), input_height(-1) {}
+       virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height) {
+               assert(input_num == 0);
+               input_width = width;
+               input_height = height;
+       }
+       virtual string effect_type_id() const { return "SizeStoringEffect"; }
+
+       int input_width, input_height;
+};
+
+TEST(EffectChainTest, SameInputsGiveSameOutputs) {
+       float data[2 * 2] = {
+               0.0f, 0.0f,
+               0.0f, 0.0f,
+       };
+       float out_data[2 * 2];
+       
+       EffectChainTester tester(NULL, 4, 3);  // Note non-square aspect.
+
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       FlatInput *input1 = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 2, 2);
+       input1->set_pixel_data(data);
+       
+       FlatInput *input2 = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 2, 2);
+       input2->set_pixel_data(data);
+
+       SizeStoringEffect *input_store = new SizeStoringEffect();
+
+       tester.get_chain()->add_input(input1);
+       tester.get_chain()->add_input(input2);
+       tester.get_chain()->add_effect(new AddEffect(), input1, input2);
+       tester.get_chain()->add_effect(input_store);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       EXPECT_EQ(2, input_store->input_width);
+       EXPECT_EQ(2, input_store->input_height);
+}
+
+TEST(EffectChainTest, AspectRatioConversion) {
+       float data1[4 * 3] = {
+               0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f,
+       };
+       float data2[7 * 7] = {
+               0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
+               0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
+       };
+
+       // The right conversion here is that the 7x7 image decides the size,
+       // since it is the biggest, so everything is scaled up to 9x7
+       // (keep the height, round the width 9.333 to 9). 
+       float out_data[9 * 7];
+       
+       EffectChainTester tester(NULL, 4, 3);
+
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       FlatInput *input1 = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 4, 3);
+       input1->set_pixel_data(data1);
+       
+       FlatInput *input2 = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 7, 7);
+       input2->set_pixel_data(data2);
+
+       SizeStoringEffect *input_store = new SizeStoringEffect();
+
+       tester.get_chain()->add_input(input1);
+       tester.get_chain()->add_input(input2);
+       tester.get_chain()->add_effect(new AddEffect(), input1, input2);
+       tester.get_chain()->add_effect(input_store);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       EXPECT_EQ(9, input_store->input_width);
+       EXPECT_EQ(7, input_store->input_height);
+}
+
+// An effect that does nothing except changing its output sizes.
+class VirtualResizeEffect : public Effect {
+public:
+       VirtualResizeEffect(int width, int height, int virtual_width, int virtual_height)
+               : width(width),
+                 height(height),
+                 virtual_width(virtual_width),
+                 virtual_height(virtual_height) {}
+       virtual string effect_type_id() const { return "VirtualResizeEffect"; }
+       string output_fragment_shader() { return read_file("identity.frag"); }
+
+       virtual bool changes_output_size() const { return true; }
+
+       virtual void get_output_size(unsigned *width, unsigned *height,
+                                    unsigned *virtual_width, unsigned *virtual_height) const {
+               *width = this->width;
+               *height = this->height;
+               *virtual_width = this->virtual_width;
+               *virtual_height = this->virtual_height;
+       }
+
+private:
+       int width, height, virtual_width, virtual_height;
+};
+
+TEST(EffectChainTest, VirtualSizeIsSentOnToInputs) {
+       const int size = 2, bigger_size = 3;
+       float data[size * size] = {
+               1.0f, 0.0f,
+               0.0f, 1.0f,
+       };
+       float out_data[size * size];
+       
+       EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       SizeStoringEffect *size_store = new SizeStoringEffect();
+
+       tester.get_chain()->add_effect(new VirtualResizeEffect(size, size, bigger_size, bigger_size));
+       tester.get_chain()->add_effect(size_store);
+       tester.get_chain()->add_effect(new VirtualResizeEffect(size, size, size, size));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       EXPECT_EQ(bigger_size, size_store->input_width);
+       EXPECT_EQ(bigger_size, size_store->input_height);
+
+       // If the resize is implemented as non-virtual, we'll fail here,
+       // since bilinear scaling from 2x2 → 3x3 → 2x2 is not very exact.
+       expect_equal(data, out_data, size, size);
+}
+
+extern bool movit_initialized;
+
+// Does not use EffectChainTest, so that it can construct an EffectChain without
+// a shared ResourcePool (which is also properly destroyed afterwards).
+// Also turns on debugging to test that code path.
+TEST(EffectChainTest, IdentityWithOwnPool) {
+       const int width = 3, height = 2;
+       float data[] = {
+               0.0f, 0.25f, 0.3f,
+               0.75f, 1.0f, 1.0f,
+       };
+       const float expected_data[] = {
+               0.75f, 1.0f, 1.0f,
+               0.0f, 0.25f, 0.3f,
+       };
+       float out_data[6];
+
+       EffectChain chain(width, height);
+       movit_initialized = false;
+       init_movit(".", MOVIT_DEBUG_ON);
+
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       FlatInput *input = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, width, height);
+       input->set_pixel_data(data);
+       chain.add_input(input);
+       chain.add_output(format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
+
+       GLuint texnum, fbo;
+       glGenTextures(1, &texnum);
+       check_error();
+       glBindTexture(GL_TEXTURE_2D, texnum);
+       check_error();
+       glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+       check_error();
+
+       glGenFramebuffers(1, &fbo);
+       check_error();
+       glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+       check_error();
+       glFramebufferTexture2D(
+               GL_FRAMEBUFFER,
+               GL_COLOR_ATTACHMENT0,
+               GL_TEXTURE_2D,
+               texnum,
+               0);
+       check_error();
+       glBindFramebuffer(GL_FRAMEBUFFER, 0);
+       check_error();
+
+       chain.finalize();
+
+       chain.render_to_fbo(fbo, width, height);
+
+       glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+       glReadPixels(0, 0, width, height, GL_RED, GL_FLOAT, out_data);
+
+       expect_equal(expected_data, out_data, width, height);
+
+       // Reset the debug status again.
+       movit_initialized = false;
+       init_movit(".", MOVIT_DEBUG_OFF);
+}