94 lines
2.4 KiB
C
94 lines
2.4 KiB
C
#include "main.h"
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#include "gfx.h"
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// forward declarations
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// input
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int checkQuit();
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// time
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float time();
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int main()
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{
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int width = 420;
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int height = 420;
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// create a window and opengl context
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SDL_Window* window = gfxInit(width, height);
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// create a texture for the compute shader to write to
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GLuint textureOutput = createWriteOnlyTexture(width, height);
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printWorkGroupLimits();
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// compile shader programs
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unsigned int computeProgram = compileComputeShaderProgram(
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"bin/res/rt.compute");
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unsigned int quadProgram = compileQuadShaderProgram(
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"bin/res/shader.vert",
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"bin/res/shader.frag");
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// initialise quad
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initBuffers();
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setVertexAttributes();
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// render loop
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while (!checkQuit())
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{
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glUseProgram(computeProgram);
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// update uniforms
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float t = time(); // time
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float sin_t = sin(t);
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int tLocation = glGetUniformLocation(computeProgram, "t");
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glUniform4f(tLocation, t, sin_t, (1.0 + sin_t)*0.5, 0.0f);
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// form view space axes
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vec3 u,v;
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vec3 up = {0,1.0,0};
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vec3 w = {0,sin_t*0.1,-1.0};
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glm_vec3_norm(w);
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glm_vec3_cross(up,w,u);
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glm_vec3_norm(u);
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glm_vec3_cross(w, u, v);
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int wLocation = glGetUniformLocation(computeProgram, "w");
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glUniform3f(wLocation+0, w[0], w[1], w[2]); // w
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glUniform3f(wLocation+1, u[0], u[1], u[2]); // u
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glUniform3f(wLocation+2, v[0], v[1], v[2]); // v
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// dispatch compute shader
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glDispatchCompute((GLuint)width, (GLuint)height, 1);
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// make sure we're finished writing to the texture before trying to read it
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glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
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// normal drawing pass
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glUseProgram(quadProgram);
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glActiveTexture(GL_TEXTURE0); // use computed texture
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glBindTexture(GL_TEXTURE_2D, textureOutput);
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glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
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// swip swap
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SDL_GL_SwapWindow(window);
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}
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return 0;
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}
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float time()
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{
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return (float)SDL_GetTicks() / 1000.0f; // ms / 1000.0 = seconds since start
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}
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int checkQuit()
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{
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SDL_Event event;
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if (SDL_PollEvent(&event) && event.type == SDL_QUIT) return 1;
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return 0;
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}
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