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rendering: make shared GL infrastructure profile-safe #15

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0115a9f
rendering: make shared GL infrastructure profile-safe
tritao Aug 8, 2026
8378d36
tests: validate core offscreen readback
tritao Aug 8, 2026
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8 changes: 4 additions & 4 deletions .github/workflows/continuous-integration-workflow.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -45,10 +45,10 @@ jobs:
sudo apt-get -y update
sudo apt-get -y install freeglut3-dev
cmake -S . -B cmake_build_dir -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DCOIN_BUILD_LEGACY_GL_RENDERER=OFF -DCOIN_BUILD_TESTS=ON -DCOIN_BUILD_EXAMPLES=OFF -DCOIN_BUILD_DOCUMENTATION=OFF
- name: Build core EGL and GLSL tests
run: cmake --build cmake_build_dir --target EGLBindingTest GLSLRuntimeTest --config Release -- -j4
- name: Run core EGL and GLSL tests
run: ctest -C Release -R '^(EGLBindingTest|GLSLRuntimeTest)$' --output-on-failure
- name: Build core EGL, GLSL, and readback tests
run: cmake --build cmake_build_dir --target EGLBindingTest GLSLRuntimeTest OffscreenReadbackTest --config Release -- -j4
- name: Run core EGL, GLSL, and readback tests
run: ctest -C Release -R '^(EGLBindingTest|GLSLRuntimeTest|OffscreenReadbackTest)$' --output-on-failure
working-directory: cmake_build_dir
env:
COIN_EGL: 1
Expand Down
31 changes: 22 additions & 9 deletions src/glue/gl.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5321,14 +5321,25 @@ cc_glglue_is_texture_size_legal(const cc_glglue * glw,
GLenum internalformat;
GLenum format;
GLenum type = GL_UNSIGNED_BYTE;
const SbBool legacy = cc_glglue_context_supports_legacy_rendering(glw);

switch (bytespertexel) {
default:
case 1:
format = internalformat = GL_LUMINANCE;
if (legacy) {
format = internalformat = GL_LUMINANCE;
} else {
internalformat = GL_R8;
format = GL_RED;
}
break;
case 2:
format = internalformat = GL_LUMINANCE_ALPHA;
if (legacy) {
format = internalformat = GL_LUMINANCE_ALPHA;
} else {
internalformat = GL_RG8;
format = GL_RG;
}
break;
case 3:
format = internalformat = GL_RGB8;
Expand Down Expand Up @@ -5403,13 +5414,14 @@ GLint coin_glglue_get_internal_texture_format(const cc_glglue * glw,
SbBool compress)
{
GLenum format;
const SbBool legacy = cc_glglue_context_supports_legacy_rendering(glw);
if (compress) {
switch (numcomponents) {
case 1:
format = GL_COMPRESSED_LUMINANCE_ARB;
format = legacy ? GL_COMPRESSED_LUMINANCE_ARB : GL_COMPRESSED_RED;
break;
case 2:
format = GL_COMPRESSED_LUMINANCE_ALPHA_ARB;
format = legacy ? GL_COMPRESSED_LUMINANCE_ALPHA_ARB : GL_COMPRESSED_RG;
break;
case 3:
format = GL_COMPRESSED_RGB_ARB;
Expand All @@ -5424,10 +5436,10 @@ GLint coin_glglue_get_internal_texture_format(const cc_glglue * glw,
SbBool usenewenums = glglue_allow_newer_opengl(glw) && cc_glglue_glversion_matches_at_least(glw,1,1,0);
switch (numcomponents) {
case 1:
format = usenewenums ? GL_LUMINANCE8 : GL_LUMINANCE;
format = legacy ? (usenewenums ? GL_LUMINANCE8 : GL_LUMINANCE) : GL_R8;
break;
case 2:
format = usenewenums ? GL_LUMINANCE8_ALPHA8 : GL_LUMINANCE_ALPHA;
format = legacy ? (usenewenums ? GL_LUMINANCE8_ALPHA8 : GL_LUMINANCE_ALPHA) : GL_RG8;
break;
case 3:
format = usenewenums ? GL_RGB8 : GL_RGB;
Expand All @@ -5445,15 +5457,16 @@ GLint coin_glglue_get_internal_texture_format(const cc_glglue * glw,
Convert from num components to client texture format for use
in glTexImage*D's format parameter.
*/
GLenum coin_glglue_get_texture_format(const cc_glglue * COIN_UNUSED_ARG(glw), int numcomponents)
GLenum coin_glglue_get_texture_format(const cc_glglue * glw, int numcomponents)
{
GLenum format;
const SbBool legacy = cc_glglue_context_supports_legacy_rendering(glw);
switch (numcomponents) {
case 1:
format = GL_LUMINANCE;
format = legacy ? GL_LUMINANCE : GL_RED;
break;
case 2:
format = GL_LUMINANCE_ALPHA;
format = legacy ? GL_LUMINANCE_ALPHA : GL_RG;
break;
case 3:
format = GL_RGB;
Expand Down
222 changes: 128 additions & 94 deletions src/rendering/CoinOffscreenGLCanvas.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -331,105 +331,139 @@ CoinOffscreenGLCanvas::readPixels(uint8_t * dst,
unsigned int dstrowsize,
unsigned int nrcomponents) const
{
glPushAttrib(GL_ALL_ATTRIB_BITS);

// First reset all settings that can influence the result of a
// glReadPixels() call, to make sure we get the actual contents of
// the buffer, unmodified.
//
// The values set up below matches the default settings of an
// OpenGL driver.

glPixelStorei(GL_PACK_SWAP_BYTES, 0);
glPixelStorei(GL_PACK_LSB_FIRST, 0);
glPixelStorei(GL_PACK_ROW_LENGTH, (GLint)dstrowsize);
glPixelStorei(GL_PACK_SKIP_ROWS, 0);
glPixelStorei(GL_PACK_SKIP_PIXELS, 0);

// FIXME: should use best possible alignment, for speediest
// operation. 20050617 mortene.
// glPixelStorei(GL_PACK_ALIGNMENT, 4);
glPixelStorei(GL_PACK_ALIGNMENT, 1);

glPixelTransferi(GL_MAP_COLOR, 0);
glPixelTransferi(GL_MAP_STENCIL, 0);
glPixelTransferi(GL_INDEX_SHIFT, 0);
glPixelTransferi(GL_INDEX_OFFSET, 0);
glPixelTransferf(GL_RED_SCALE, 1);
glPixelTransferf(GL_RED_BIAS, 0);
glPixelTransferf(GL_GREEN_SCALE, 1);
glPixelTransferf(GL_GREEN_BIAS, 0);
glPixelTransferf(GL_BLUE_SCALE, 1);
glPixelTransferf(GL_BLUE_BIAS, 0);
glPixelTransferf(GL_ALPHA_SCALE, 1);
glPixelTransferf(GL_ALPHA_BIAS, 0);
glPixelTransferf(GL_DEPTH_SCALE, 1);
glPixelTransferf(GL_DEPTH_BIAS, 0);

GLuint i = 0;
GLfloat f = 0.0f;
glPixelMapfv(GL_PIXEL_MAP_I_TO_I, 1, &f);
glPixelMapuiv(GL_PIXEL_MAP_S_TO_S, 1, &i);
glPixelMapfv(GL_PIXEL_MAP_I_TO_R, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_I_TO_G, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_I_TO_B, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_I_TO_A, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_R_TO_R, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_G_TO_G, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_B_TO_B, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_A_TO_A, 1, &f);

// The flushing of the OpenGL pipeline before and after the
// glReadPixels() call is done as a work-around for a reported
// OpenGL driver bug: on a Win2000 system with ATI Radeon graphics
// card, the system would hang hard if the flushing was not done.
//
// This is obviously an OpenGL driver bug, but the workaround of
// doing excessive flushing has no real ill effects, so we just do
// it unconditionally for all drivers. Note that it might not be
// necessary to flush both before and after glReadPixels() to work
// around the bug (this was not established with the external
// reporter), but again it shouldn't matter if we do.
//
// For reference, the specific driver which was reported to fail has
// the following characteristics:
//
// GL_VENDOR="ATI Technologies Inc."
// GL_RENDERER="Radeon 9000 DDR x86/SSE2"
// GL_VERSION="1.3.3446 Win2000 Release"
//
// mortene.

glFlush(); glFinish();

assert((nrcomponents >= 1) && (nrcomponents <= 4));
#if defined(COIN_BUILD_LEGACY_GL_RENDERER)
const cc_glglue * glue = cc_glglue_instance((int) this->renderid);
const SbBool legacyContext = cc_glglue_context_supports_legacy_rendering(glue);
if (legacyContext) {
glPushAttrib(GL_PIXEL_MODE_BIT);
}
#endif

if (nrcomponents < 3) {
unsigned char * tmp = new unsigned char[vpdims[0]*vpdims[1]*4];
glReadPixels(0, 0, vpdims[0], vpdims[1],
nrcomponents == 1 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, tmp);
GLint packSwapBytes;
GLint packLsbFirst;
GLint packRowLength;
GLint packSkipRows;
GLint packSkipPixels;
GLint packAlignment;
glGetIntegerv(GL_PACK_SWAP_BYTES, &packSwapBytes);
glGetIntegerv(GL_PACK_LSB_FIRST, &packLsbFirst);
glGetIntegerv(GL_PACK_ROW_LENGTH, &packRowLength);
glGetIntegerv(GL_PACK_SKIP_ROWS, &packSkipRows);
glGetIntegerv(GL_PACK_SKIP_PIXELS, &packSkipPixels);
glGetIntegerv(GL_PACK_ALIGNMENT, &packAlignment);

// First reset all settings that can influence the result of a
// glReadPixels() call, to make sure we get the actual contents of
// the buffer, unmodified.
//
// The values set up below matches the default settings of an
// OpenGL driver.

glPixelStorei(GL_PACK_SWAP_BYTES, 0);
glPixelStorei(GL_PACK_LSB_FIRST, 0);
glPixelStorei(GL_PACK_ROW_LENGTH, (GLint)dstrowsize);
glPixelStorei(GL_PACK_SKIP_ROWS, 0);
glPixelStorei(GL_PACK_SKIP_PIXELS, 0);

// FIXME: should use best possible alignment, for speediest
// operation. 20050617 mortene.
// glPixelStorei(GL_PACK_ALIGNMENT, 4);
glPixelStorei(GL_PACK_ALIGNMENT, 1);

#if defined(COIN_BUILD_LEGACY_GL_RENDERER)
if (legacyContext) {
glPixelTransferi(GL_MAP_COLOR, 0);
glPixelTransferi(GL_MAP_STENCIL, 0);
glPixelTransferi(GL_INDEX_SHIFT, 0);
glPixelTransferi(GL_INDEX_OFFSET, 0);
glPixelTransferf(GL_RED_SCALE, 1);
glPixelTransferf(GL_RED_BIAS, 0);
glPixelTransferf(GL_GREEN_SCALE, 1);
glPixelTransferf(GL_GREEN_BIAS, 0);
glPixelTransferf(GL_BLUE_SCALE, 1);
glPixelTransferf(GL_BLUE_BIAS, 0);
glPixelTransferf(GL_ALPHA_SCALE, 1);
glPixelTransferf(GL_ALPHA_BIAS, 0);
glPixelTransferf(GL_DEPTH_SCALE, 1);
glPixelTransferf(GL_DEPTH_BIAS, 0);

GLuint i = 0;
GLfloat f = 0.0f;
glPixelMapfv(GL_PIXEL_MAP_I_TO_I, 1, &f);
glPixelMapuiv(GL_PIXEL_MAP_S_TO_S, 1, &i);
glPixelMapfv(GL_PIXEL_MAP_I_TO_R, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_I_TO_G, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_I_TO_B, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_I_TO_A, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_R_TO_R, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_G_TO_G, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_B_TO_B, 1, &f);
glPixelMapfv(GL_PIXEL_MAP_A_TO_A, 1, &f);
}
#endif

const unsigned char * src = tmp;
// manually convert to grayscale
for (short y = 0; y < vpdims[1]; y++) {
for (short x = 0; x < vpdims[0]; x++) {
double v = src[0] * 0.3 + src[1] * 0.59 + src[2] * 0.11;
*dst++ = (unsigned char) v;
if (nrcomponents == 2) {
*dst++ = src[3];
// The flushing of the OpenGL pipeline before and after the
// glReadPixels() call is done as a work-around for a reported
// OpenGL driver bug: on a Win2000 system with ATI Radeon graphics
// card, the system would hang hard if the flushing was not done.
//
// This is obviously an OpenGL driver bug, but the workaround of
// doing excessive flushing has no real ill effects, so we just do
// it unconditionally for all drivers. Note that it might not be
// necessary to flush both before and after glReadPixels() to work
// around the bug (this was not established with the external
// reporter), but again it shouldn't matter if we do.
//
// For reference, the specific driver which was reported to fail has
// the following characteristics:
//
// GL_VENDOR="ATI Technologies Inc."
// GL_RENDERER="Radeon 9000 DDR x86/SSE2"
// GL_VERSION="1.3.3446 Win2000 Release"
//
// mortene.

glFlush(); glFinish();

assert((nrcomponents >= 1) && (nrcomponents <= 4));

if (nrcomponents < 3) {
unsigned char * tmp = new unsigned char[vpdims[0]*vpdims[1]*4];
glReadPixels(0, 0, vpdims[0], vpdims[1],
nrcomponents == 1 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, tmp);

const unsigned char * src = tmp;
// manually convert to grayscale
for (short y = 0; y < vpdims[1]; y++) {
for (short x = 0; x < vpdims[0]; x++) {
double v = src[0] * 0.3 + src[1] * 0.59 + src[2] * 0.11;
*dst++ = (unsigned char) v;
if (nrcomponents == 2) {
*dst++ = src[3];
}
src += nrcomponents == 1 ? 3 : 4;
}
src += nrcomponents == 1 ? 3 : 4;
}
delete[] tmp;
}
delete[] tmp;
}
else {
glReadPixels(0, 0, vpdims[0], vpdims[1],
nrcomponents == 3 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, dst);
}
glFlush(); glFinish();

glPopAttrib();
else {
glReadPixels(0, 0, vpdims[0], vpdims[1],
nrcomponents == 3 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, dst);
}
glFlush(); glFinish();

glPixelStorei(GL_PACK_SWAP_BYTES, packSwapBytes);
glPixelStorei(GL_PACK_LSB_FIRST, packLsbFirst);
glPixelStorei(GL_PACK_ROW_LENGTH, packRowLength);
glPixelStorei(GL_PACK_SKIP_ROWS, packSkipRows);
glPixelStorei(GL_PACK_SKIP_PIXELS, packSkipPixels);
glPixelStorei(GL_PACK_ALIGNMENT, packAlignment);

#if defined(COIN_BUILD_LEGACY_GL_RENDERER)
if (legacyContext) {
glPopAttrib();
}
#endif
}

// *************************************************************************
Expand Down
12 changes: 12 additions & 0 deletions testsuite/CMakeLists.txt
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Expand Up @@ -113,6 +113,18 @@ if(HAVE_EGL)
)
add_test(NAME GLSLRuntimeTest COMMAND GLSLRuntimeTest)
set_tests_properties(GLSLRuntimeTest PROPERTIES SKIP_RETURN_CODE 77)

add_executable(OffscreenReadbackTest offscreen-readback-test.cpp)
target_link_libraries(OffscreenReadbackTest Coin ${COIN_TARGET_LINK_LIBRARIES})
target_compile_definitions(OffscreenReadbackTest PRIVATE COIN_INTERNAL)
target_include_directories(OffscreenReadbackTest PRIVATE
${PROJECT_SOURCE_DIR}/src
${PROJECT_SOURCE_DIR}/include
${PROJECT_BINARY_DIR}/include
${COIN_TARGET_INCLUDE_DIRECTORIES}
)
add_test(NAME OffscreenReadbackTest COMMAND OffscreenReadbackTest)
set_tests_properties(OffscreenReadbackTest PROPERTIES SKIP_RETURN_CODE 77)
endif()

# Many warnings are generated from test macros on macOS with Xcode.
Expand Down
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