From 7a2b3ea8c13657ef697d0b4dc73ccada23f81039 Mon Sep 17 00:00:00 2001
From: pommicket <pommicket@gmail.com>
Date: Thu, 3 Nov 2022 19:48:26 -0400
Subject: custom shader texture

---
 gl.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

(limited to 'gl.c')

diff --git a/gl.c b/gl.c
index c16d252..1c41d54 100644
--- a/gl.c
+++ b/gl.c
@@ -5,6 +5,7 @@
 	do(DRAWARRAYS, DrawArrays)\
 	do(GENTEXTURES, GenTextures)\
 	do(DELETETEXTURES, DeleteTextures)\
+	do(GENERATEMIPMAP, GenerateMipmap)\
 	do(TEXIMAGE2D, TexImage2D)\
 	do(BINDTEXTURE, BindTexture)\
 	do(TEXPARAMETERI, TexParameteri)\
@@ -87,6 +88,29 @@ void gl_rc_sab_decref(GlRcSAB **ps) {
 	*ps = NULL;
 }
 
+GlRcTexture *gl_rc_texture_new(GLuint texture) {
+	GlRcTexture *t = calloc(1, sizeof *t);
+	t->ref_count = 1;
+	t->texture = texture;
+	return t;
+}
+
+void gl_rc_texture_incref(GlRcTexture *t) {
+	if (!t) return;
+	++t->ref_count;
+}
+
+void gl_rc_texture_decref(GlRcTexture **pt) {
+	GlRcTexture *t = *pt;
+	if (!t) return;
+	if (--t->ref_count == 0) {
+		debug_println("Delete texture %u", t->texture);
+		glDeleteTextures(1, &t->texture);
+		free(t);
+	}
+	*pt = NULL;
+}
+
 // set by main()
 static int gl_version_major;
 static int gl_version_minor;
@@ -305,3 +329,33 @@ static void gl_geometry_draw(void) {
 	
 	arr_clear(gl_geometry_triangles);
 }
+
+static GLuint gl_load_texture_from_image(const char *path) {
+	GLuint texture = 0;
+	int w=0, h=0, n=0;
+	unsigned char *data = stbi_load(path, &w, &h, &n, 4);
+	if (data && w > 0 && h > 0) {
+		size_t bytes_per_row = (size_t)w * 4;
+		unsigned char *tempbuf = calloc(1, bytes_per_row);
+		// flip image vertically
+		for (int y = 0; y < h/2; ++y) {
+			int y2 = h-1-y;
+			unsigned char *row1 = &data[y*w*4];
+			unsigned char *row2 = &data[y2*w*4];
+			memcpy(tempbuf, row1, bytes_per_row);
+			memcpy(row1, row2, bytes_per_row);
+			memcpy(row2, tempbuf, bytes_per_row);
+		}
+		free(tempbuf);
+		
+		glGenTextures(1, &texture);
+		glBindTexture(GL_TEXTURE_2D, texture);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+		free(data);
+	}
+	return texture;
+}
-- 
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