Initial commit

source/engine/skybox.c

@@ -0,0 +1,123 @@
+#include "skybox.h"
+
+#include "shader.h"
+#include "camera.h"
+#include <SDL_image.h>
+#include <string.h>
+
+#include "openglrender.h"
+
+static const float skyboxVertices[216] = {
+    -1.0f, 1.0f, -1.0f,
+    -1.0f, -1.0f, -1.0f,
+    1.0f, -1.0f, -1.0f,
+    1.0f, -1.0f, -1.0f,
+    1.0f, 1.0f, -1.0f,
+    -1.0f, 1.0f, -1.0f,
+
+    -1.0f, -1.0f, 1.0f,
+    -1.0f, -1.0f, -1.0f,
+    -1.0f, 1.0f, -1.0f,
+    -1.0f, 1.0f, -1.0f,
+    -1.0f, 1.0f, 1.0f,
+    -1.0f, -1.0f, 1.0f,
+
+    1.0f, -1.0f, -1.0f,
+    1.0f, -1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, -1.0f,
+    1.0f, -1.0f, -1.0f,
+
+    -1.0f, -1.0f, 1.0f,
+    -1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f, -1.0f, 1.0f,
+    -1.0f, -1.0f, 1.0f,
+
+    -1.0f, 1.0f, -1.0f,
+    1.0f, 1.0f, -1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    -1.0f, 1.0f, 1.0f,
+    -1.0f, 1.0f, -1.0f,
+
+    -1.0f, -1.0f, -1.0f,
+    -1.0f, -1.0f, 1.0f,
+    1.0f, -1.0f, -1.0f,
+    1.0f, -1.0f, -1.0f,
+    -1.0f, -1.0f, 1.0f,
+    1.0f, -1.0f, 1.0f
+};
+
+struct mSkybox *MakeSkybox(const char *cubemap)
+{
+    struct mSkybox *newskybox =
+	(struct mSkybox *) malloc(sizeof(struct mSkybox));
+
+    newskybox->shader = MakeShader("skyvert.glsl", "skyfrag.glsl");
+    shader_compile(newskybox->shader);
+
+    glGenVertexArrays(1, &newskybox->VAO);
+    glGenBuffers(1, &newskybox->VBO);
+    glBindVertexArray(newskybox->VAO);
+    glBindBuffer(GL_ARRAY_BUFFER, newskybox->VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(skyboxVertices), &skyboxVertices,
+		 GL_STATIC_DRAW);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float),
+			  (void *) 0);
+
+    shader_use(newskybox->shader);
+    shader_setint(newskybox->shader, "skybox", 0);
+
+    const char *faces[6] =
+	{ "right.jpg", "left.jpg", "top.jpg", "bottom.jpg", "front.jpg",
+	"back.jpg"
+    };
+
+    glGenTextures(1, &newskybox->id);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, newskybox->id);
+    char buf[100] = { '\0' };
+
+    for (unsigned int i = 0; i < 6; i++) {
+	buf[0] = '\0';
+	strcat(buf, cubemap);
+	strcat(buf, "/");
+	strcat(buf, faces[i]);
+	SDL_Surface *data = NULL;	//IMG_Load(buf);
+	glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, 2048,
+		     2048, 0, GL_RGB, GL_UNSIGNED_BYTE, data->pixels);
+	SDL_FreeSurface(data);
+    }
+
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S,
+		    GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T,
+		    GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R,
+		    GL_CLAMP_TO_EDGE);
+
+
+    return newskybox;
+}
+
+void skybox_draw(const struct mSkybox *skybox,
+		 const struct mCamera *camera)
+{
+    shader_use(skybox->shader);
+
+    mfloat_t view[16] = { 0.f };
+    getviewmatrix(view, camera);
+    shader_setmat4(skybox->shader, "skyview", view);
+
+    // skybox cube
+    glBindVertexArray(skybox->VAO);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, skybox->id);
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+    glBindVertexArray(0);
+}