From 513599d85583739611bc5e7d26c446271fb132dd Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop+git@gmail.com>
Date: Tue, 10 May 2011 23:02:32 -0400
Subject: [PATCH] split transform into modelview/projection

---
 lighting/test.cc       | 25 ++++++++++++++++---------
 lighting/v_shader.glsl |  7 ++++---
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/lighting/test.cc b/lighting/test.cc
index 48b1de2..b4c7519 100644
--- a/lighting/test.cc
+++ b/lighting/test.cc
@@ -28,12 +28,14 @@ const GLushort indices[] = {
     0, 1, 2, 3, 4, 5
 };
 GLuint program, vs, fs, data_vbo, index_vbo;
-GLint ambient_loc, diffuse_loc, specular_loc, shininess_loc, transform_loc;
+GLint ambient_loc, diffuse_loc, specular_loc, shininess_loc,
+      projection_loc, modelview_loc;
 enum Locations {
     LOC_POSITION,
     LOC_NORMAL
 };
-static guMatrix4x4 transform;
+static guMatrix4x4 projection;
+static guMatrix4x4 modelview;
 
 char * loadFile(const char *fname)
 {
@@ -133,14 +135,17 @@ bool init(int width, int height)
     glClearColor (0.0, 0.0, 0.0, 0.0);
     glEnable(GL_DEPTH_TEST);
     glViewport(0, 0, WIDTH, HEIGHT);
-    guMatrixLoadIdentity(&transform);
+    guMatrixLoadIdentity(&projection);
+    guMatrixLoadIdentity(&modelview);
     float near = 0.1;
     float scale = near * 0.577 * 2;
     float aspect = (float)width / (float)height;
-    guMatrixFrustum(&transform, -aspect * scale, aspect * scale, -scale, scale, near, 1000.0);
-//    guPerspective(&transform, 60, (float)width / (float)height, 0.1, 1000.0);
-    guMatrixTranslate(&transform, 0, 0, -1);
-//    guMatrixTranslate(&transform, 1, 0.3, 0);
+    guMatrixFrustum(&projection, -aspect * scale, aspect * scale, -scale, scale, near, 1000.0);
+#if 0
+    guPerspective(&projection, 60, (float)width / (float)height, 0.1, 1000.0);
+#endif
+    guMatrixTranslate(&modelview, 0, 0, -1);
+//    guMatrixTranslate(&modelview, 1, 0.3, 0);
 
     vs = makeShader(GL_VERTEX_SHADER, "v_shader.glsl");
     fs = makeShader(GL_FRAGMENT_SHADER, "f_shader.glsl");
@@ -175,14 +180,16 @@ bool init(int width, int height)
     diffuse_loc = glGetUniformLocation(program, "diffuse");
     specular_loc = glGetUniformLocation(program, "specular");
     shininess_loc = glGetUniformLocation(program, "shininess");
-    transform_loc = glGetUniformLocation(program, "transform");
+    projection_loc = glGetUniformLocation(program, "projection");
+    modelview_loc = glGetUniformLocation(program, "modelview");
 
     glUseProgram(program);
     glUniform4f(ambient_loc, 0.2, 0.2, 0.2, 1.0);
     glUniform4f(diffuse_loc, 1.0, 0.6, 0.0, 1.0);
     glUniform4f(specular_loc, 1.0, 1.0, 1.0, 1.0);
     glUniform1f(shininess_loc, 85.0);
-    glUniformMatrix4fv(transform_loc, 1, GL_TRUE, &transform[0][0]);
+    glUniformMatrix4fv(projection_loc, 1, GL_TRUE, &projection[0][0]);
+    glUniformMatrix4fv(modelview_loc, 1, GL_TRUE, &modelview[0][0]);
 
     data_vbo = makeBuffer(GL_ARRAY_BUFFER, data, sizeof(data));
     index_vbo = makeBuffer(GL_ELEMENT_ARRAY_BUFFER, indices, sizeof(indices));
diff --git a/lighting/v_shader.glsl b/lighting/v_shader.glsl
index 014d5e1..95fe566 100644
--- a/lighting/v_shader.glsl
+++ b/lighting/v_shader.glsl
@@ -1,5 +1,6 @@
 
-uniform mat4 transform;
+uniform mat4 projection;
+uniform mat4 modelview;
 
 attribute vec3 pos;
 attribute vec3 normal;
@@ -9,7 +10,7 @@ varying vec3 normal_i;
 
 void main(void)
 {
-    gl_Position = transform * vec4(pos, 1);
+    gl_Position = projection * modelview * vec4(pos, 1);
     pos_i = vec3(gl_Position.x, gl_Position.y, gl_Position.z);
-    normal_i = vec3(transform * vec4(normal, 0.0));
+    normal_i = vec3(modelview * vec4(normal, 0.0));
 }