From 801a56a78fbbde2e7348b3bf483c7263abc3c55d Mon Sep 17 00:00:00 2001
From: mmcwilliams <hi@mmcwilliams.com>
Date: Mon, 1 Apr 2024 11:00:11 -0400
Subject: [PATCH] Display quad, full screen

---
 main.cpp | 44 +++++++++++++-------------------------------
 1 file changed, 13 insertions(+), 31 deletions(-)

diff --git a/main.cpp b/main.cpp
index 1be44d1..3dac895 100644
--- a/main.cpp
+++ b/main.cpp
@@ -23,19 +23,17 @@ GLuint imageTexture;
  
 void displayMe(void)
 {
-    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
-    glClear(GL_COLOR_BUFFER_BIT);
-    glTexImage2D(       GL_TEXTURE_2D,       // Type of texture
-                        0,                   // Pyramid level (for mip-mapping) - 0 is the top level
-                        GL_RGB,              // Internal colour format to convert to
-                        image.cols,          // Image width  i.e. 640 for Kinect in standard mode
-                        image.rows,          // Image height i.e. 480 for Kinect in standard mode
-                        0,                   // Border width in pixels (can either be 1 or 0)
-                        GL_RGB,              // Input image format (i.e. GL_RGB, GL_RGBA, GL_BGR etc.)
-                        GL_UNSIGNED_BYTE,    // Image data type
-                        image.ptr());        // The actual image data itself
-    glEnd();
-    glFlush();
+  // Set every pixel in the frame buffer to the current clear color.
+  glClear(GL_COLOR_BUFFER_BIT);
+  glBegin(GL_POLYGON);
+    glColor3f(1, 0, 0); glVertex3f(-1.0, -1.0, 0.5);
+    glColor3f(0, 1, 0); glVertex3f(1.0, -1.0, 0);
+    glColor3f(0, 0, 1); glVertex3f(1.0, 1.0, 0);
+    glVertex3f(-1.0, 1.0, 0);
+  glEnd();
+
+  // Flush drawing command buffer to make drawing happen as soon as possible.
+  glFlush();
 }
  
 int main(int argc, char** argv)
@@ -43,33 +41,17 @@ int main(int argc, char** argv)
     string image_path = samples::findFile("chart.png");
     Mat image = imread(image_path, IMREAD_COLOR);
 
-    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
-    glGenTextures(1, &imageTexture);
-    glBindTexture(GL_TEXTURE_2D, imageTexture);
-
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-    // Set texture clamping method
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
-
 #if (CV_VERSION_MAJOR >= 4)
     cvtColor(image, image, cv::COLOR_BGR2RGB);
 #else
     cvtColor(image, image, CV_BGR2RGB);
 #endif
-
-    //GLint dims[4] = {0};
-    //glGetIntegerv(GL_VIEWPORT, dims);
-    //GLint fbWidth = dims[2];
-    //GLint fbHeight = dims[3];
-    //cout << fbWidth << "," << fbHeight << endl;
+ 
     glutInit(&argc, argv);
     glutInitDisplayMode(GLUT_SINGLE);
     glutInitWindowSize(1920, 1080);
     glutInitWindowPosition(0, 0);
-    glutCreateWindow("Hello world!");
+    glutCreateWindow("opengl_opencv_example");
     glutFullScreen();
 
     glutDisplayFunc(displayMe);