1. rcrnstn/fbo3d
  2. Commit f2567f2392acf44537001685704dbfad32287bc8
Browse code

Add implementation

Robert Cranston authored on 07/04/2021 05:14:16
Showing 9 changed files
tests/glfbo3d.cpp
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+#include <cstddef>
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+#include <string>
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+#include <vector>
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+
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+#include <GL/glew.h>
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+#include <glm/glm.hpp>
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+
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+#include <glfbo3d.hpp>
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+#include <glshader.hpp>
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+#include <gltest.hpp>
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+
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+
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+constexpr auto size = 256;
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+constexpr auto fbo_size_divisor = 2;
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+
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+
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+static void draw(GLuint texture0)
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+{
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+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
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+    glViewport(0, 0, size, size);
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+    glActiveTexture(GL_TEXTURE0 + 0);
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+    glBindTexture(GL_TEXTURE_3D, texture0);
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+    auto draw = Shader({
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+        "draw.vert",
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+        "draw.geom", "quad.geom",
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+        "draw.frag",
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+    });
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+    draw
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+        .use()
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+        .uniform("texture0", 0);
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+    auto t = 0.0F;
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+    gltest_set_time(t);
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+    while ((t = gltest_get_time()) < 1)
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+    {
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+        draw
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+            .uniform("z", t * 2 - 1, false)
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+            .validate();
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+        glDrawArrays(GL_TRIANGLES, 0, 3);
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+        gltest_swap_buffers();
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+    }
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+}
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+
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+
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+GLTEST(3, 2, size, size, glfbo3d)
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+{
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+    // Settings.
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+    Shader::root("tests/shaders");
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+    auto fbo_size = glm::ivec3(size / fbo_size_divisor);
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+
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+    // Create and bind vertex array.
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+    auto vertex_array = GLuint{};
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+    glGenVertexArrays(1, &vertex_array);
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+    glBindVertexArray(vertex_array);
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+
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+    // Create texture.
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+    auto texture0 = GLuint{};
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+    glGenTextures(1, &texture0);
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+    glBindTexture(GL_TEXTURE_3D, texture0);
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+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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+    glTexImage3D(
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+        GL_TEXTURE_3D, 0, GL_RGBA32F,
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+        fbo_size.x, fbo_size.y, fbo_size.z, 0,
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+        GL_RGBA, GL_FLOAT, nullptr
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+    );
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+
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+    // Create framebuffer.
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+    auto framebuffer = GLuint{};
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+    glGenFramebuffers(1, &framebuffer);
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+    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
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+    glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture0, 0);
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+
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+    // Set with CPU and draw.
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+    auto data = std::vector<glm::vec4>{};
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+    data.reserve((size_t)(fbo_size.x * fbo_size.y * fbo_size.z));
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+    for (int z = 0; z < fbo_size.z; ++z)
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+        for (int y = 0; y < fbo_size.y; ++y)
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+            for (int x = 0; x < fbo_size.x; ++x)
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+                data.emplace_back(
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+                    x / (fbo_size.x / 8) % 2 ^ // NOLINT
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+                    y / (fbo_size.y / 4) % 2 ^ // NOLINT
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+                    z / (fbo_size.z / 2) % 2   // NOLINT
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+                );
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+    glBindTexture(GL_TEXTURE_3D, texture0);
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+    glTexSubImage3D(
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+        GL_TEXTURE_3D, 0,
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+        0, 0, 0, fbo_size.x, fbo_size.y, fbo_size.z,
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+        GL_RGBA, GL_FLOAT, &data[0]
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+    );
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+    draw(texture0);
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+
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+    // Set with GPU and draw.
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+    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
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+    glViewport(0, 0, fbo_size.x, fbo_size.y);
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+    auto instance_count = fbo_size.z;
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+    auto set = Shader({
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+        "set.vert",
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+        "set.geom", "quad.geom",
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+        "set.frag",
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+    });
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+    set
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+        .use()
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+        .uniform("instance_count", instance_count)
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+        .validate();
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+    glDrawArraysInstanced(GL_TRIANGLES, 0, 3, instance_count);
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+    draw(texture0);
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+
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+    // Delete.
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+    glDeleteFramebuffers(1, &framebuffer);
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+    glDeleteTextures(1, &texture0);
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+    glDeleteVertexArrays(1, &vertex_array);
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+}
tests/shaders/draw.frag
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+#version 150
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+
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+
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+uniform sampler3D texture0;
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+uniform float z;
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+
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+
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+in vec3 position;
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+
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+
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+out vec4 frag_color;
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+
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+
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+void main()
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+{
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+    frag_color = texture(texture0, (vec3(position.xy, z) + 1) / 2);
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+}
tests/shaders/draw.geom
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+#version 150
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+
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+#extension GL_ARB_shading_language_include : require
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+
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+
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+#include "quad.geom.h"
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+
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+
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+void main()
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+{
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+    quad(0, 1);
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+}
tests/shaders/draw.vert
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+#version 150
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+
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+
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+void main()
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+{
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+}
tests/shaders/quad.geom
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+#version 150
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+
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+
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+#define QUAD_EMIT_VERTEX_(X, Y, Z, LAYER) position = vec3(X, Y, Z); gl_Position = vec4(position, 1); gl_Layer = LAYER; EmitVertex();
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+
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+
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+layout(triangles) in;
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+layout(triangle_strip, max_vertices = 4) out;
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+
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+
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+out vec3 position;
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+
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+
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+void quad(int layer, int layer_count)
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+{
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+    float z = (layer + 0.5) / layer_count * 2 - 1;
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+    QUAD_EMIT_VERTEX_(-1, -1, z, layer);
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+    QUAD_EMIT_VERTEX_(-1, +1, z, layer);
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+    QUAD_EMIT_VERTEX_(+1, -1, z, layer);
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+    QUAD_EMIT_VERTEX_(+1, +1, z, layer);
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+    EndPrimitive();
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+}
tests/shaders/quad.geom.h
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+#ifndef QUAD_H_
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+#define QUAD_H_
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+
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+
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+void quad(int layer, int layer_count);
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+
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+
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+#endif // QUAD_H_
tests/shaders/set.frag
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+#version 150
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+
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+
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+in vec3 position;
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+
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+
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+out vec4 frag_color;
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+
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+
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+void main()
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+{
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+    frag_color = vec4(vec3(length(position)), 1);
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+}
tests/shaders/set.geom
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+#version 150
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+
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+#extension GL_ARB_shading_language_include : require
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+
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+
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+#include "quad.geom.h"
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+
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+
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+uniform int instance_count;
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+
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+
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+in int instance_id[];
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+
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+
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+void main()
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+{
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+    quad(instance_id[0], instance_count);
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+}
tests/shaders/set.vert
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+#version 150
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+
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+
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+out int instance_id;
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+
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+
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+void main()
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+{
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+    instance_id = gl_InstanceID;
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+}