X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=init.cpp;h=c5e81135dccb1de327883715f735a8e9506be41b;hp=3c781e125bb45a366da2d04229da3cfe7f99bbb6;hb=a5f32397f9c23fa8644fe195865d6c36685cf866;hpb=cf3b8245a92407da567cf8843335911dd1a0da23

diff --git a/init.cpp b/init.cpp
index 3c781e1..c5e8113 100644
--- a/init.cpp
+++ b/init.cpp
@@ -38,7 +38,7 @@ void measure_texel_subpixel_precision()
 	check_error();
 	glBindTexture(GL_TEXTURE_2D, dst_texnum);
 	check_error();
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, width, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, width, 1, 0, GL_RGBA, GL_FLOAT, NULL);
 	check_error();
 
 	glGenFramebuffers(1, &fbo);
@@ -122,14 +122,14 @@ void measure_texel_subpixel_precision()
 	// Now read the data back and see what the card did.
 	// (We only look at the red channel; the others will surely be the same.)
 	// We assume a linear ramp; anything else will give sort of odd results here.
-	float out_data[width];
-	glReadPixels(0, 0, width, 1, GL_RED, GL_FLOAT, out_data);
+	float out_data[width * 4];
+	glReadPixels(0, 0, width, 1, GL_RGBA, GL_FLOAT, out_data);
 	check_error();
 
 	float biggest_jump = 0.0f;
 	for (unsigned i = 1; i < width; ++i) {
-		assert(out_data[i] >= out_data[i - 1]);
-		biggest_jump = max(biggest_jump, out_data[i] - out_data[i - 1]);
+		assert(out_data[i * 4] >= out_data[(i - 1) * 4]);
+		biggest_jump = max(biggest_jump, out_data[i * 4] - out_data[(i - 1) * 4]);
 	}
 
 	assert(biggest_jump > 0.0);
@@ -221,12 +221,6 @@ void measure_roundoff_problems()
 		1.0f, 1.0f,
 		1.0f, 0.0f
 	};
-	float texcoords[] = {
-		0.25f, 0.0f,
-		0.25f, 0.0f,
-		0.75f, 0.0f,
-		0.75f, 0.0f
-	};
 
 	GLuint vao;
 	glGenVertexArrays(1, &vao);
@@ -235,7 +229,7 @@ void measure_roundoff_problems()
 	check_error();
 
 	GLuint position_vbo = fill_vertex_attribute(glsl_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
-	GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(texcoords), texcoords);
+	GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same data.
 
 	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 	check_error();
@@ -248,16 +242,16 @@ void measure_roundoff_problems()
 
 	// Now read the data back and see what the card did. (Ignore the last value.)
 	// (We only look at the red channel; the others will surely be the same.)
-	unsigned char out_data[512];
-	glReadPixels(0, 0, 512, 1, GL_RED, GL_UNSIGNED_BYTE, out_data);
+	unsigned char out_data[512 * 4];
+	glReadPixels(0, 0, 512, 1, GL_RGBA, GL_UNSIGNED_BYTE, out_data);
 	check_error();
 
 	int wrongly_rounded = 0;
 	for (unsigned i = 0; i < 255; ++i) {
-		if (out_data[i * 2 + 0] != i) {
+		if (out_data[(i * 2 + 0) * 4] != i) {
 			++wrongly_rounded;
 		}
-		if (out_data[i * 2 + 1] != i + 1) {
+		if (out_data[(i * 2 + 1) * 4] != i + 1) {
 			++wrongly_rounded;
 		}
 	}