Back to full image size buffers, and range support in shader

4 files changed, 55 insertions, 30 deletions

diff --git a/BuddhaTest/Shaders/BuddhaCompute.glsl b/BuddhaTest/Shaders/BuddhaCompute.glsl
index 91c1195..8b342cc 100644
--- a/BuddhaTest/Shaders/BuddhaCompute.glsl
+++ b/BuddhaTest/Shaders/BuddhaCompute.glsl
@@ -12,6 +12,11 @@ layout(std430, binding=3) restrict buffer brightnessData
     restrict uint brightness;
 };
 
+layout(std430, binding=4) restrict buffer importanceMapBufferBlock
+{
+    restrict uint importanceMap[];
+};
+
 /** Data stored in the state buffer. */
 struct individualData
 {
@@ -34,6 +39,8 @@ uniform uvec4 orbitLength;
 uniform uint iterationsPerDispatch;
 uniform uint totalIterations;
 
+uniform vec4 imageRange = vec4(-2.0,-1.125,2.0,1.125);
+
 /** Data stored in shared memory. Used to reduce register pressure. Read at beginning from buffer (if needed), written back at end. */
 struct workerState
 {
@@ -54,6 +61,17 @@ void uintMaxIP(inout uvec3 modified, const uvec3 constant)
         uintMaxIP(modified[i],constant[i]);
 }
 
+void addToImportanceMap(vec2 orbitParameter)
+{
+    //as starting point values are in x [-2:2] and y [0:2], importance map has an aspect ratio of 2:1
+    float width = sqrt(float(2*(importanceMap.length() - 1)));
+    //float height = 0.5*width;
+    orbitParameter *= vec2(0.25,0.5);
+    orbitParameter.x += 0.5;
+    //now both components are between 0 and 1
+
+}
+
 void addToColorOfCell(uvec2 cell, uvec3 toAdd)
 {
     uint firstIndex = 3*(cell.x + cell.y * width);
@@ -70,7 +88,7 @@ void addToColorOfCell(uvec2 cell, uvec3 toAdd)
 
 uvec2 getCell(vec2 complex)
 {
-    vec2 uv = clamp(vec2((complex.x+2.5)/3.5, (abs(complex.y))),vec2(0.0),vec2(1.0));
+    vec2 uv = clamp(vec2((complex.x-imageRange[0])/(imageRange[2]-imageRange[0]), (complex.y-imageRange[1])/(imageRange[3]-imageRange[1])),vec2(0.0),vec2(1.0));
     return uvec2(width * uv.x, height * uv.y);
 }
 
@@ -236,7 +254,7 @@ bool drawOrbit(in vec2 offset, in uint totalIterations, inout vec2 lastVal, inou
             doneIterations = i+1;
             return true; //done.
         }
-        if(lastVal.x > -2.5 && lastVal.x < 1.0 && lastVal.y > -1.0 && lastVal.y < 1.0)
+        if(lastVal.x > imageRange[0] && lastVal.x < imageRange[2] && lastVal.y > imageRange[1] && lastVal.y < imageRange[3])
         {
             addToColorAt(lastVal,uvec3(i < orbitLength.r,i < orbitLength.g,i < orbitLength.b));
         }
@@ -253,7 +271,7 @@ vec2 getCurrentOrbitOffset(const uint orbitNumber, const uint totalWorkers, cons
     seed = (seed ^ (intHash(orbitNumber+totalWorkers)));
     float y = hash1(seed,seed);
     vec2 random = vec2(x,y);
-    return vec2(random.x * 3.5-2.5,random.y*1.55);
+    return vec2(random.x * 4-2,random.y*2);
 }
 
 void main() {
diff --git a/BuddhaTest/Shaders/BuddhaFragment.glsl b/BuddhaTest/Shaders/BuddhaFragment.glsl
index 52a0354..ac8114b 100644
--- a/BuddhaTest/Shaders/BuddhaFragment.glsl
+++ b/BuddhaTest/Shaders/BuddhaFragment.glsl
@@ -21,14 +21,17 @@ uniform float colorScale;
 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 yIndex = uint(max(0.0,abs(fragCoord.y+1.0)*0.5*height));
     uint firstIndex = 3*(xIndex + yIndex * width);
-    return uvec3(counts_SSBO[firstIndex],counts_SSBO[firstIndex+1],counts_SSBO[firstIndex+2]);
+    uvec3 c1=uvec3(counts_SSBO[firstIndex],counts_SSBO[firstIndex+1],counts_SSBO[firstIndex+2]);
+    firstIndex = 3*(xIndex +(height-1 - yIndex) * width);
+    uvec3 c2=uvec3(counts_SSBO[firstIndex],counts_SSBO[firstIndex+1],counts_SSBO[firstIndex+2]);
+    return c1+c2;
 }
 
 void main(){
     uvec3 totalCount = getColorAt(uv);
 
-    vec3 scaled = pow(min(vec3(1.0),colorScale*vec3(totalCount)/max(float(brightness),1.0)),vec3(gamma));
+    vec3 scaled = pow(min(vec3(1.0),colorScale*0.5*vec3(totalCount)/max(float(brightness),1.0)),vec3(gamma));
     color = scaled;
 }
diff --git a/BuddhaTest/src/BuddhaTest.cpp b/BuddhaTest/src/BuddhaTest.cpp
index 2064d06..ac7cebe 100644
--- a/BuddhaTest/src/BuddhaTest.cpp
+++ b/BuddhaTest/src/BuddhaTest.cpp
@@ -26,8 +26,6 @@ int main(int argc, char * argv[])
         return 2;
     }
 
-    unsigned int bufferHeight = settings.imageHeight/2;
-
     GLFWwindow* window;
 
     /* Initialize the library */
@@ -61,7 +59,7 @@ int main(int argc, char * argv[])
 
     //we have a context. Let's check if input is sane.
     //calcualte buffer size, and make sure it's allowed by the driver.
-    const unsigned int pixelCount{(settings.imageWidth * bufferHeight)};
+    const unsigned int pixelCount{(settings.imageWidth * settings.imageHeight)};
     if(!settings.CheckValidity())
     {
         glfwTerminate();
@@ -126,6 +124,13 @@ int main(int argc, char * argv[])
     glClearBufferData(GL_SHADER_STORAGE_BUFFER,GL_R8,GL_RED,GL_UNSIGNED_INT,nullptr);
     glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 3, brightnessBuffer);
 
+    GLuint importanceMapBuffer;
+    glGenBuffers(1,&importanceMapBuffer);
+    glBindBuffer(GL_SHADER_STORAGE_BUFFER,importanceMapBuffer);
+    glBufferData(GL_SHADER_STORAGE_BUFFER,4*8193,nullptr, GL_DYNAMIC_COPY); //128*64+1. one larger than the map itself -> max brightness. Aspect 2:1 because mandel is symmetric around x
+    glClearBufferData(GL_SHADER_STORAGE_BUFFER,GL_R8,GL_RED,GL_UNSIGNED_INT,nullptr);
+    glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 4, brightnessBuffer);
+
     //the state buffer is special. While making each entry 8 bytes large and using std430 layout, the data is never read back,
     //so we can get away with being more lenient and allowing the compiler to choose layout without much extra work.
     //We need to query the size for allocation though.
@@ -155,7 +160,7 @@ int main(int argc, char * argv[])
     GLint iterationsPerDispatchHandle = glGetUniformLocation(ComputeShader, "iterationsPerDispatch");
     glUniform4ui(orbitLengthUniformHandle,settings.orbitLengthRed,settings.orbitLengthGreen,settings.orbitLengthBlue,settings.orbitLengthSkip);
     glUniform1ui(widthUniformComputeHandle, settings.imageWidth);
-    glUniform1ui(heightUniformComputeHandle, bufferHeight);
+    glUniform1ui(heightUniformComputeHandle, settings.imageHeight);
 
     const uint32_t maxOrbitlength = std::max(std::max(settings.orbitLengthBlue,settings.orbitLengthGreen),settings.orbitLengthRed);
     glUniform1ui(totalIterationsUniformHandle, maxOrbitlength);
@@ -166,7 +171,7 @@ int main(int argc, char * argv[])
     GLint gammaUniformFragmentHandle = glGetUniformLocation(VertexAndFragmentShaders, "gamma");
     GLint colorScaleUniformFragmentHandle = glGetUniformLocation(VertexAndFragmentShaders, "colorScale");
     glUniform1ui(widthUniformFragmentHandle, settings.imageWidth);
-    glUniform1ui(heightUniformFragmentHandle, bufferHeight);
+    glUniform1ui(heightUniformFragmentHandle, settings.imageHeight);
     glUniform1f(gammaUniformFragmentHandle, float(settings.pngGamma));
     glUniform1f(colorScaleUniformFragmentHandle,float(settings.pngColorScale));
 
@@ -251,7 +256,7 @@ int main(int argc, char * argv[])
             Helpers::PrintBenchmarkScore(readBackBuffer);
 
         if(!settings.pngFilename.empty())
-            Helpers::WriteOutputPNG(settings.pngFilename,readBackBuffer,settings.imageWidth,bufferHeight, settings.pngGamma, settings.pngColorScale);
+            Helpers::WriteOutputPNG(settings.pngFilename,readBackBuffer,settings.imageWidth,settings.imageHeight, settings.pngGamma, settings.pngColorScale);
     }
 
     //a bit of cleanup
diff --git a/BuddhaTest/src/Helpers.cpp b/BuddhaTest/src/Helpers.cpp
index b4c39c0..bd667fb 100644
--- a/BuddhaTest/src/Helpers.cpp
+++ b/BuddhaTest/src/Helpers.cpp
@@ -169,9 +169,9 @@ namespace Helpers
 
     void WriteOutputPNG(const std::string &path, const std::vector<uint32_t>& data, unsigned int width, unsigned int bufferHeight, double gamma, double colorScale)
     {
-        std::vector<png_byte> pngData(3*width*2*bufferHeight);
-        std::vector<png_byte *> rows{2*bufferHeight};
-        for(unsigned int i = 0; i < 2*bufferHeight ; ++i)
+        std::vector<png_byte> pngData(3*width*bufferHeight);
+        std::vector<png_byte *> rows{bufferHeight};
+        for(unsigned int i = 0; i < bufferHeight ; ++i)
         {
             rows[i] = pngData.data()+3*width*i;
         }
@@ -181,22 +181,21 @@ namespace Helpers
         {
             maxValue = std::max(maxValue,data[i]);
         }
-        for(unsigned int i = 0; i < data.size();++i)
-        {
-            if(fabs(gamma - 1.0) > 0.0001 || fabs(colorScale - 1.0) > 0.0001)
-            {
-                pngData[data.size() + i] = static_cast<png_byte>(255.0 * pow(std::min(1.0,colorScale*static_cast<double>(data[i])/static_cast<double>(maxValue)),gamma));
-            }
-            else
-            {
-                pngData[data.size() + i] = (255*data[i] + (maxValue/2))/maxValue;
-            }
-        }
-        for(unsigned int i = 0; i < bufferHeight;++i)
+        for(unsigned int row = 0; row < bufferHeight/2; ++row)
         {
-            for(unsigned int j = 0; j < width*3;++j)
+            unsigned int otherRow = bufferHeight - 1-row;
+            for(unsigned int col=0;col < width*3; ++col)
             {
-                rows[i][j] =rows[2*bufferHeight-i-1][j];
+                double c = 0.5*(data[col + row*width*3] + data[col + otherRow*width*3]);
+                if(fabs(gamma - 1.0) > 0.0001 || fabs(colorScale - 1.0) > 0.0001)
+                {
+                    pngData[col + row*width*3] = static_cast<png_byte>(255.0 * pow(std::min(1.0,colorScale*c/static_cast<double>(maxValue)),gamma));
+                }
+                else
+                {
+                    pngData[col + row*width*3] = (255*c + (maxValue/2))/maxValue;
+                }
+                pngData[col+otherRow*width*3] = pngData[col + row*width*3];
             }
         }
 
@@ -223,7 +222,7 @@ namespace Helpers
             return;
         }
         png_init_io(png_ptr, fd.Get());
-        png_set_IHDR(png_ptr, info_ptr, width, 2*bufferHeight, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+        png_set_IHDR(png_ptr, info_ptr, width, bufferHeight, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
         png_write_info(png_ptr, info_ptr);
         //header written.