Split buffer in three, one per color (as OpenGL guarantees that one can at least have 8 SSBOs), to allow three times larger images. Also make it possible to ignore maximum buffer size reported by the driver.

The maximum buffer size limitation is rather strict on radeonsi, so I decided to split the buffer in three, effectively increasing the maximum image size by a factor of three.
While doing so I realized that at least on radeonsi the reported maximum buffer size seems to be off. For this reason I added a new command line switch, that allows to ignore the maximum buffer size check.
For those curious: radeonsi reports a maximum buffer size of 128 MB, but I had no problems when using three buffers of 1098 MB each.

1 files changed, 12 insertions, 4 deletions

diff --git a/BuddhaTest/Shaders/BuddhaFragment.glsl b/BuddhaTest/Shaders/BuddhaFragment.glsl
index 1556065..24fb6a7 100644
--- a/BuddhaTest/Shaders/BuddhaFragment.glsl
+++ b/BuddhaTest/Shaders/BuddhaFragment.glsl
@@ -4,9 +4,17 @@ in vec2 uv;
 

 out vec3 color;

 

-layout(std430, binding=2) buffer renderedData

+layout(std430, binding=2) buffer renderedDataRed

 {

-        uint counts_SSBO[];

+        uint counts_SSBORed[];

+};

+layout(std430, binding=3) buffer renderedDataGreen

+{

+        uint counts_SSBOGreen[];

+};

+layout(std430, binding=4) buffer renderedDataBlue

+{

+        uint counts_SSBOBlue[];

 };

 

 uniform uint width;

@@ -16,8 +24,8 @@ uvec3 getColorAt(vec2 fragCoord)
 {

     uint xIndex = uint(max(0.0,(fragCoord.x+1.0)*0.5*width));

     uint yIndex = uint(max(0.0,abs(fragCoord.y)*height));

-    uint firstIndex = 3*(xIndex + yIndex * width);

-    return uvec3(counts_SSBO[firstIndex],counts_SSBO[firstIndex+1],counts_SSBO[firstIndex+2]);

+    uint firstIndex = (xIndex + yIndex * width);

+    return uvec3(counts_SSBORed[firstIndex],counts_SSBOGreen[firstIndex],counts_SSBOBlue[firstIndex]);

 }

 

 void main(){