opengl

commit 2785631a14bd5bc2863f2f2ea6c7847189703d25
parent de129c37493ff9583111691e52c16f0dd379f953
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Wed, 28 Jun 2023 12:01:18 +0900

add perspective

Diffstat:
M
glm.c
 | 
29
+++++++++++++++++++++++++++++
M
glm.h
 | 
3
+++
M
main.c
 | 
32
++++++++++++++++++++++++--------
M
main.h
 | 
1
+
M
shader.c
 | 
8
++++++++

5 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/glm.c b/glm.c
@@ -155,6 +155,23 @@ matMakeIdent(int size)
 	return m;
 }
 
+mat *
+matMakePers(float fov, float aspect, float near, float far)
+{
+	mat *m = (mat *)malloc(sizeof(mat));
+	m->data = (float *)calloc(sizeof(float), 16);
+	m->data[0] = 1 / (aspect * tanf(fov/2));
+	m->data[5] = 1 / tanf(fov/2);
+	m->data[10] = -(far + near) / (far - near);
+	m->data[11] = -1;
+	m->data[14] = -(2 * far * near) / (far - near);
+	
+	m->size = 4;
+	numMat++;
+	return m;
+}
+
+
 void
 matFree(mat *m)
 {
@@ -237,3 +254,15 @@ rotate(mat *m, float rad, vec *axis)
 	matFree(rot);
 	return m;
 }
+
+mat *
+scale(mat *m, float s)
+{
+	mat *scl = matMakeIdent(m->size);
+	for (int i = 0; i < m->size; i++) {
+		scl->data[i + m->size*i] = s;
+	}
+	matDot(m, scl);
+	matFree(scl);
+	return m;
+}
diff --git a/glm.h b/glm.h
@@ -30,7 +30,9 @@ vec *vecCross(vec *v, const vec *w);
 char *matStr(char *s, mat *m);
 mat *matMake(float *data, int size);
 mat *matMakeIdent(int size);
+mat *matMakePers(float fov, float aspect, float near, float far);
 void matFree(mat *m);
+mat *matDot(mat *m, const mat *n);
 int matCount(void);
 
 mat *matCopy(const mat *m);
@@ -39,3 +41,4 @@ float *matDataPtr(mat *m);
 mat *translate(mat *m, const vec *v);
 // axis must be an unit vector
 mat *rotate(mat *m, float rad, vec *axis);
+mat *scale(mat *m, float s);
diff --git a/main.c b/main.c
@@ -50,6 +50,9 @@ processInput(GLFWwindow *window)
 int
 main(void)
 {
+	int width = 600;
+	int height = 600;
+	
 	float vertices[] = {
 		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
 		0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
@@ -94,13 +97,21 @@ main(void)
 		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f
 	};
 	
-	int numCube = 2;
+	int numCube = 3;
 	vec *cubePositions[numCube];
-	cubePositions[0] = vecMake((float []){0.0, 0.0, 0.0}, 3);
-	cubePositions[1] = vecMake((float []){0.5, 0.5, 0.0}, 3);
+	cubePositions[0] = vecMake((float []){-2.0, 0.0, -10.0}, 3);
+	cubePositions[1] = vecMake((float []){0.0, 3.0, -20.0}, 3);
+	cubePositions[2] = vecMake((float []){1.0, 1.0, -2.0}, 3);
 	mat *modelMat[numCube];
-	for (int i = 0; i < numCube; i++)
-		modelMat[i] = translate(matMakeIdent(4), cubePositions[i]);
+	for (int i = 0; i < numCube; i++) {
+		modelMat[i] = scale(matMakeIdent(4), 0.1);
+		translate(modelMat[i], cubePositions[i]);
+	}
+	mat *viewMat = matMakeIdent(4);
+	mat *projMat = matMakePers((float)M_PI*80/180, (float)width/(float)height,
+		0.1, 100.0);
+	char s[256];
+	printf("%s", matStr(s, projMat));
 
 	vec *axis0 = vecMake((float[]){1.41421356/2, 1.41421356/2, 0.0}, 3);
 	vec *axis1 = vecMake((float[]){0.0, 0.0, 1.0}, 3);
@@ -112,7 +123,8 @@ main(void)
 	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 	
 	// create glfw window
-	GLFWwindow *window = glfwCreateWindow(600, 600, "opengl", NULL, NULL);
+	GLFWwindow *window = glfwCreateWindow(width, height, "opengl",
+		NULL, NULL);
 	if (window == NULL) {
 		fprintf(stderr, "main: failed to open window\n");
 		glfwTerminate();
@@ -202,8 +214,10 @@ main(void)
 				rotation += now-lastTime;
 			}
 			rotate(transform, rotation, axis0);
-			glUniformMatrix4fv(tloc, 1, GL_FALSE,
-				matDataPtr(transform));
+			
+			ShaderSetMat4(shader, "model", matDataPtr(transform));
+			ShaderSetMat4(shader, "view", matDataPtr(viewMat));
+			ShaderSetMat4(shader, "proj", matDataPtr(projMat));
 			glDrawArrays(GL_TRIANGLES, 0, 36);
 			matFree(transform);
 		}
@@ -219,6 +233,8 @@ main(void)
 		vecFree(cubePositions[i]);
 		matFree(modelMat[i]);
 	}
+	matFree(viewMat);
+	matFree(projMat);
 	
 	glDeleteVertexArrays(1, &VAO);
 	glDeleteBuffers(1, &VBO);
diff --git a/main.h b/main.h
@@ -12,4 +12,5 @@ Shader *ShaderInit(const char *vs, const char *fs);
 void ShaderUse(Shader *s);
 void ShaderDelete(Shader *s);
 void ShaderSetFloat(Shader *s, const char *name, float value);
+void ShaderSetMat4(Shader *s, const char *name, float *mat);
 
diff --git a/shader.c b/shader.c
@@ -140,3 +140,10 @@ ShaderSetFloat(Shader *s, const char *name, float value)
 {
 	glUniform1f(glGetUniformLocation(s->ID, name), value);
 }
+
+void
+ShaderSetMat4(Shader *s, const char *name, float *mat)
+{
+	glUniformMatrix4fv(glGetUniformLocation(s->ID, name), 1,
+		GL_FALSE, mat);
+}
+\ No newline at end of file