1 files changed, 117 insertions, 0 deletions
diff --git a/src/canvas.h b/src/canvas.h
new file mode 100644
index 0000000..84dbe56
--- /dev/null
+++ b/src/canvas.h
@@ -0,0 +1,117 @@
+//
+// Created by saintruler on 04.05.19.
+//
+
+#ifndef OPENGLTEST_CANVAS_H
+#define OPENGLTEST_CANVAS_H
+
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+
+#include <iostream>
+
+struct Color
+{
+    unsigned int r = 0, g = 0, b = 0;
+};
+
+class Canvas
+{
+public:
+    Canvas(int width, int height)
+    {
+//        vertices = {
+//            // positions        // colors           // texture coords
+//            1.f,  1.f, 0.0f,    1.0f, 0.0f, 0.0f,   1.0f, 1.0f, // top right
+//            1.f, -1.f, 0.0f,    0.0f, 1.0f, 0.0f,   1.0f, 0.0f, // bottom right
+//            -1.f, -1.f, 0.0f,   0.0f, 0.0f, 1.0f,   0.0f, 0.0f, // bottom left
+//            -1.f,  1.f, 0.0f,   1.0f, 1.0f, 0.0f,   0.0f, 1.0f  // top left
+//        };
+//
+//        indices = {
+//            0, 1, 3, // first triangle
+//            1, 2, 3  // second triangle
+//        };
+
+        glGenVertexArrays(1, &VAO);
+        glGenBuffers(1, &VBO);
+        glGenBuffers(1, &EBO);
+
+        glBindVertexArray(VAO);
+
+        glBindBuffer(GL_ARRAY_BUFFER, VBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
+
+        // position attribute
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+        glEnableVertexAttribArray(0);
+        // color attribute
+        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+        glEnableVertexAttribArray(1);
+        // texture coord attribute
+        glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+        glEnableVertexAttribArray(2);
+
+
+        this->width = width;
+        this->height = height;
+
+        canvas = (unsigned char*) malloc(width * height * 3);
+        glGenTextures(1, &texture);
+    }
+
+    void SetPixel(int x, int y, Color color)
+    {
+        canvas[y * width * 3 + x * 3 + 0] = color.r;
+        canvas[y * width * 3 + x * 3 + 1] = color.g;
+        canvas[y * width * 3 + x * 3 + 2] = color.b;
+
+        UpdateTexture();
+    }
+
+    void UpdateTexture()
+    {
+        // all upcoming GL_TEXTURE_2D operations now have effect on this texture object
+        glBindTexture(GL_TEXTURE_2D, texture);
+
+        // set texture wrapping to GL_REPEAT (default wrapping method)
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+        // set texture filtering parameters
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, width, 0, GL_RGB, GL_UNSIGNED_BYTE, canvas);
+        glGenerateMipmap(GL_TEXTURE_2D);
+    }
+
+    void DrawTexture()
+    {
+        glBindTexture(GL_TEXTURE_2D, texture);
+        // render container
+//        ourShader.use();
+        glBindVertexArray(VAO);
+        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+    }
+
+    unsigned int* GetTexture()
+    {
+        return &(this->texture);
+    }
+
+private:
+    int width, height;
+    unsigned char* canvas;
+    unsigned int texture;
+
+    unsigned int VBO, VAO, EBO;
+
+    float* vertices;
+    unsigned int* indices;
+};
+
+#endif //OPENGLTEST_CANVAS_H