Set DrawBuffers for each fragment color output

Update the DrawBuffers call to properly map the fragment color
output to it expected color attachment

Affects:

KHR-GL45.enhanced_layouts.fragment_data_location_api

Components: OpenGL

VK-GL-CTS issue: 517

Change-Id: I54678528b59b9732fbe466df1a50707a3a4716ba

diff --git a/external/openglcts/modules/gl/gl4cEnhancedLayoutsTests.cpp b/external/openglcts/modules/gl/gl4cEnhancedLayoutsTests.cpp
index 4686f5b..a9246c1 100644 (file)
--- a/external/openglcts/modules/gl/gl4cEnhancedLayoutsTests.cpp
+++ b/external/openglcts/modules/gl/gl4cEnhancedLayoutsTests.cpp
@@ -19331,16 +19331,18 @@ void FragmentDataLocationAPITest::prepareFramebuffer(Utils::Framebuffer& framebu
 
        /* Set up drawbuffers */
        const Functions& gl = m_context.getRenderContext().getFunctions();
-       //  1. There are only 4 outputs in fragment shader, so only need to do buffer mapping for 4 attachments,
-       //  2. another issue is each output variable has a location, it is the fragment color index, so the index of
-       //  GL_COLOR_ATTACHMENT in glDrawBuffers() should keep the same with the location, to make test correct,
-       //  we needt to change the above code of glDrawBuffers() as :
-       GLint  buffers_size = 4;
-       GLenum buffers[]        = { GLenum(GL_COLOR_ATTACHMENT0 + m_chichi_location),
-                                                GLenum(GL_COLOR_ATTACHMENT0 + m_goku_location),
-                                                GLenum(GL_COLOR_ATTACHMENT0 + m_goten_location),
-                                                GLenum(GL_COLOR_ATTACHMENT0 + m_gohan_location) };
-       gl.drawBuffers(buffers_size, buffers);
+       // The fragment shader can have more than 4 color outputs, but it only care about 4 (goku, gohan, goten, chichi).
+       // We will first initialize all draw buffers to NONE and then set the real value for the 4 outputs we care about
+       GLint maxDrawBuffers = 0;
+       gl.getIntegerv(GL_MAX_DRAW_BUFFERS, &maxDrawBuffers);
+
+       std::vector<GLenum> buffers(maxDrawBuffers, GL_NONE);
+       buffers[m_chichi_location] = GLenum(GL_COLOR_ATTACHMENT0 + m_chichi_location);
+       buffers[m_goten_location]  = GLenum(GL_COLOR_ATTACHMENT0 + m_goten_location);
+       buffers[m_goku_location]   = GLenum(GL_COLOR_ATTACHMENT0 + m_goku_location);
+       buffers[m_gohan_location]  = GLenum(GL_COLOR_ATTACHMENT0 + m_gohan_location);
+
+       gl.drawBuffers(maxDrawBuffers, buffers.data());
        GLU_EXPECT_NO_ERROR(gl.getError(), "DrawBuffers");
 }