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);
// 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);
// 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;
}
}