]> git.sesse.net Git - movit/blobdiff - effect_chain_test.cpp
Add proper formats for sRGB without alpha.
[movit] / effect_chain_test.cpp
index 614bffc3dd5ecfe08143062af0ebda767ffb9970..50d004db1c52c1192946b87add1b785149f585fc 100644 (file)
@@ -2,14 +2,24 @@
 //
 // Note that this also contains the tests for some of the simpler effects.
 
-#include <GL/glew.h>
+#include <epoxy/gl.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 "test_util.h"
+#include "util.h"
+
+using namespace std;
+
+namespace movit {
 
 TEST(EffectChainTest, EmptyChain) {
        float data[] = {
@@ -27,8 +37,8 @@ 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) {
@@ -48,8 +58,8 @@ 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; }
 };
@@ -88,8 +98,8 @@ 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.
@@ -103,8 +113,8 @@ template<class T>
 class RewritingEffect : public Effect {
 public:
        RewritingEffect() : effect(new T()), replaced_node(NULL) {}
-       virtual std::string effect_type_id() const { return "RewritingEffect[" + effect->effect_type_id() + "]"; }
-       std::string output_fragment_shader() { EXPECT_TRUE(false); return read_file("identity.frag"); }
+       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) {
                replaced_node = graph->add_node(effect);
                graph->replace_receiver(self, replaced_node);
@@ -142,19 +152,23 @@ TEST(EffectChainTest, RewritingWorksAndGammaConversionsAreInserted) {
 
 TEST(EffectChainTest, RewritingWorksAndTexturesAreAskedForsRGB) {
        unsigned char data[] = {
-               0, 64,
-               128, 255,
+                 0,   0,   0, 255,
+                64,  64,  64, 255,
+               128, 128, 128, 255,
+               255, 255, 255, 255,
        };
-       float expected_data[4] = {
-               1.0f, 0.9771f,
-               0.8983f, 0.0f,
+       float expected_data[] = {
+               1.0000f, 1.0000f, 1.0000f, 1.0000f,
+               0.9771f, 0.9771f, 0.9771f, 1.0000f,
+               0.8983f, 0.8983f, 0.8983f, 1.0000f,
+               0.0000f, 0.0000f, 0.0000f, 1.0000f
        };
-       float out_data[2];
-       EffectChainTester tester(NULL, 2, 2);
-       tester.add_input(data, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
+       float out_data[4 * 4];
+       EffectChainTester tester(NULL, 1, 4);
+       tester.add_input(data, FORMAT_RGBA_POSTMULTIPLIED_ALPHA, 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);
+       tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_sRGB);
 
        Node *node = effect->replaced_node;
        ASSERT_EQ(1, node->incoming_links.size());
@@ -162,7 +176,7 @@ TEST(EffectChainTest, RewritingWorksAndTexturesAreAskedForsRGB) {
        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);
+       expect_equal(expected_data, out_data, 4, 4);
 }
 
 TEST(EffectChainTest, RewritingWorksAndColorspaceConversionsAreInserted) {
@@ -197,7 +211,7 @@ public:
            : FlatInput(format, pixel_format, type, width, height),
              overridden_color_space(format.color_space),
              overridden_gamma_curve(format.gamma_curve) {}
-       virtual std::string effect_type_id() const { return "UnknownColorspaceInput"; }
+       virtual string effect_type_id() const { return "UnknownColorspaceInput"; }
 
        void set_color_space(Colorspace colorspace) {
                overridden_color_space = colorspace;
@@ -213,7 +227,7 @@ private:
        GammaCurve overridden_gamma_curve;
 };
 
-TEST(EffectChainTester, HandlesInputChangingColorspace) {
+TEST(EffectChainTest, HandlesInputChangingColorspace) {
        const int size = 4;
 
        float data[size] = {
@@ -344,7 +358,7 @@ TEST(EffectChainTest, IdentityThroughAlphaConversions) {
                0.0f, 0.2f, 0.2f, 0.3f,
                0.1f, 0.0f, 1.0f, 1.0f,
        };
-       float out_data[6];
+       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);
@@ -382,8 +396,8 @@ TEST(EffectChainTest, NoAlphaConversionsWhenPremultipliedAlphaNotNeeded) {
 class BlueInput : public Input {
 public:
        BlueInput() { register_int("needs_mipmaps", &needs_mipmaps); }
-       virtual std::string effect_type_id() const { return "IdentityEffect"; }
-       std::string output_fragment_shader() { return read_file("blue.frag"); }
+       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; }
@@ -400,9 +414,9 @@ private:
 // which outputs blank alpha.
 class RewritingToBlueInput : public Input {
 public:
-       RewritingToBlueInput() { register_int("needs_mipmaps", &needs_mipmaps); }
-       virtual std::string effect_type_id() const { return "RewritingToBlueInput"; }
-       std::string output_fragment_shader() { EXPECT_TRUE(false); return read_file("identity.frag"); }
+       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);
@@ -439,7 +453,7 @@ TEST(EffectChainTest, NoAlphaConversionsWithBlankAlpha) {
        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_PREMULTIPLIED);
+       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());
@@ -448,23 +462,91 @@ TEST(EffectChainTest, NoAlphaConversionsWithBlankAlpha) {
        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)
+
+       // To be allowed to mess with the sampler state.
+       virtual bool needs_texture_bounce() const { return true; }
+
+       virtual string effect_type_id() const { return "MipmapNeedingEffect"; }
+       string output_fragment_shader() { return read_file("mipmap_needing_effect.frag"); }
+       virtual void inform_added(EffectChain *chain) { this->chain = chain; }
+
+       void set_gl_state(GLuint glsl_program_num, const string& prefix, unsigned *sampler_num)
        {
-               glActiveTexture(GL_TEXTURE0);
+               Node *self = chain->find_node_for_effect(this);
+               glActiveTexture(chain->get_input_sampler(self, 0));
                check_error();
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
                check_error();
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
                check_error();
        }
+
+private:
+       EffectChain *chain;
 };
 
 TEST(EffectChainTest, MipmapGenerationWorks) {
@@ -576,24 +658,12 @@ TEST(EffectChainTest, ResizeDownByFourThenUpByFour) {
        expect_equal(expected_data, out_data, 4, 16);
 }
 
-// An effect that multiplies with a constant. Used below.
-class MultiplyEffect : public Effect {
-public:
-       MultiplyEffect() { register_float("factor", &factor); }
-       virtual std::string effect_type_id() const { return "MultiplyEffect"; }
-       std::string output_fragment_shader() { return read_file("multiply.frag"); }
-       virtual AlphaHandling alpha_handling() const { return DONT_CARE_ALPHA_TYPE; }
-
-private:
-       float factor;
-};
-
 // An effect that adds its two inputs together. Used below.
 class AddEffect : public Effect {
 public:
        AddEffect() {}
-       virtual std::string effect_type_id() const { return "AddEffect"; }
-       std::string output_fragment_shader() { return read_file("add.frag"); }
+       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; }
 };
@@ -618,11 +688,14 @@ TEST(EffectChainTest, DiamondGraph) {
        };
        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_float("factor", 0.5f));
+       ASSERT_TRUE(mul_half->set_vec4("factor", half));
        
        MultiplyEffect *mul_two = new MultiplyEffect();
-       ASSERT_TRUE(mul_two->set_float("factor", 2.0f));
+       ASSERT_TRUE(mul_two->set_vec4("factor", two));
 
        EffectChainTester tester(NULL, 2, 2);
 
@@ -664,11 +737,14 @@ TEST(EffectChainTest, DiamondGraphWithOneInputUsedInTwoPhases) {
        };
        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_float("factor", 0.5f));
+       ASSERT_TRUE(mul_half->set_vec4("factor", half));
        
        MultiplyEffect *mul_two = new MultiplyEffect();
-       ASSERT_TRUE(mul_two->set_float("factor", 2.0f));
+       ASSERT_TRUE(mul_two->set_vec4("factor", two));
        
        BouncingIdentityEffect *bounce = new BouncingIdentityEffect();
 
@@ -756,3 +832,213 @@ TEST(EffectChainTest, EffectUsedTwiceOnlyGetsOneColorspaceConversion) {
        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);
+}
+
+// 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], temp[6 * 4];
+
+       EffectChain chain(width, height);
+       movit_debug_level = 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_FLOAT, 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);
+       check_error();
+       glReadPixels(0, 0, width, height, GL_RGBA, GL_FLOAT, temp);
+       check_error();
+       for (unsigned i = 0; i < 6; ++i) {
+               out_data[i] = temp[i * 4];
+       }
+
+       expect_equal(expected_data, out_data, width, height);
+
+       // Reset the debug status again.
+       movit_debug_level = MOVIT_DEBUG_OFF;
+}
+
+}  // namespace movit